(https://i.imgur.com/VENK1Nf.jpg)
Disclaimer: this thread contains numerous broken links because I'm bad at the internet.
Objective
The purpose of this primer is to summarize the design and play fundamentals for the classic arcade game Zoo Keeper in hope of generating more interest in the game and help shortcut its rather steep learning curve.
Additionally, I mean to formalize a Zoo Keeper lexicon so that future talk of strategy and tactics can be easily communicated.
This is... a work in progress.
Overview
I intended to write my own introduction for Zoo Keeper, but after looking around the net I decided such work had already been done many times over. For instance, this excerpt from Wikipedia is actually pretty good: Zoo Keeper is an arcade game created by Taito America and released in 1982. In the game's storyline, the player's character, named Zeke, is a zookeeper whose girlfriend, Zelda, has been kidnapped by a malicious monkey. To distract Zeke, the monkey has unlocked the cages in the zoo, allowing the animals to escape. The player must control Zeke to run, jump, build walls, and collect bonus items in an effort to recapture and contain the animals before finally rescuing Zelda.
In 2005, the game was ported as part of the Taito Legends arcade game collection for PlayStation 2, Xbox, and home PCs.
Gameplay
Zoo Keeper has three different types of stages. In the zoo stage, Zeke must run around the edges of the screen to build up the zoo's outer wall and keep the animals from escaping as they try to break through it from inside. Each of these stages is timed, with items appearing periodically that can be picked up for bonus points. One item is always a net; if Zeke picks this up, he can use it for a few seconds to capture animals and put them back in the cage. Multiple nets appear in later zoo stages. When time runs out, the player earns bonus points for every animal that is not outside the wall perimeter. Points are also earned for jumping over animals.
After every second zoo stage, the player enters a stage in which the goal is to maneuver Zeke from the bottom of the screen to a platform at top center, where Zelda is tied to a tree. All platforms except the top one scroll across the screen, some carrying bonus items; the player scores points for moving from one level to another (up or down), grabbing items, and touching Zelda to rescue her. At the same time, a monkey throws down coconuts that bounce among the platforms and must be avoided.
After every platform stage except the first, the player enters a bonus stage with several escalators and a cage in front of each one. Zeke must cross the screen to get to each escalator, jumping over both the animals running toward him and the cage itself. Zelda waits for him at the top of the last escalator; if he reaches her, the player earns an extra life. The first bonus stage has two escalators, the second one has three, and all subsequent bonus stages have four.
A life is lost if Zeke touches an animal without holding a net, is hit by a coconut, or falls off the bottom edge of the screen.
Also, here is a rather amusing video introduction: http://www.collegehumor.com/video/6427551/bleep-bloop-zoo-keeper (http://www.collegehumor.com/video/6427551/bleep-bloop-zoo-keeper)
along with a basic strategy guide from StrategyWiki: http://strategywiki.org/wiki/Zoo_Keeper (http://strategywiki.org/wiki/Zoo_Keeper)
an informational packet from CoinOpSpace which includes a PDF of the original Zoo Keeper manual: http://www.coinopspace.com/group/zookeeper (http://www.coinopspace.com/group/zookeeper)
and a blog devoted entirely to one man's quest to become the greatest Zoo Keeper player in the world: https://web.archive.org/web/20120225173627/http://www.keeperofthezoo.com/ (https://web.archive.org/web/20120225173627/http://www.keeperofthezoo.com/)
From these assorted introductions I need to clarify that I will be referring to the "zoo stages" as the Rounds (because that is what they are called in-game and I think it's clever, as Zeke goes round and round while building the zoo wall), the "platform stages" as the Coconut boards, and the "bonus stages" as the Escalator boards.
The board types, in the order they are encountered in the game, are outlined below.
Round 1/Elephant Board/Beer Board
(https://i.imgur.com/Dli7zHK.jpg)
Prize Potential: to earn maximum point value, prizes must be gathered in order. This is true for every Round in Zoo Keeper.
#1 120pts.
#2 250pts.
#3 500pts.
#4 1000pts.
Notes: Players will get "1 Free Try" on this board if they are trampled by an elephant before the Net appears. First appearance of the Elephant, the slowest animal in Zoo Keeper, worth 250pts. if captured at Round's end. Board spawns only Elephants. Zeke builds wall in two-brick layers, so several passes over the same area are required for the wall to reach its maximum 9-brick thickness.
Round 2/Snake Board/Clover Board
(https://i.imgur.com/KopWDUY.jpg)
Prize Potential:
#1 250pts.
#2 500pts.
#3 1000pts.
#4 2000pts.
Notes: First appearance of the Snake, the second slowest animal in Zoo Keeper, worth 500pts. if captured at Round's end. Board spawns a mix of Elephants and Snakes. Zeke builds wall in two-brick layers.
1st Coconut Board/Purple Coconut Board
(https://i.imgur.com/ITmdi39.jpg)
(https://i.imgur.com/50Eo2wX.jpg)
*The top-level platform on all Coconut boards awards successively higher point values (up to 300,000pts.) for each additional time the platform is landed on after Zeke has landed upon a platform of a different level. In fact, every level of platform will continue to award landing points so long as Zeke changes levels between jumps. Even the bottom-level platform awards landing points, though those figures are not included in the Coconut board stats.
I apologize for the inconsistency here, where I refer to platform-levels in the one image and just platforms in the next.
Round 3/Camel Board/Sundae Board
(https://i.imgur.com/LMKFxlE.jpg)
Prize Potential:
#1 500pts.
#2 1000pts.
#3 2000pts.
#4 4000pts.
Notes: First Round that begins with no wall built. First appearance of the Camel, the third slowest animal in Zoo Keeper, worth 1000pts. if captured at Round's end. Board spawns a mix of Elephants, Snakes, and Camels. Zeke builds wall in three-brick layers.
Round 4/Rhino Board/Watermelon Board
(https://i.imgur.com/oPqLROl.jpg)
Prize Potential:
#1 1000pts.
#2 2000pts.
#3 4000pts.
#4 8000pts.
Notes: First appearance of the Rhino, the third fastest animal in Zoo Keeper, worth 2000pts. if captured at Round's end. Board spawns a mix of Elephants, Snakes, Camels, and Rhinos. Zeke builds wall in three-brick layers.
2nd Coconut Board/Green Coconut Board
(https://i.imgur.com/BQsfi1x.jpg)
(https://i.imgur.com/6Z6Vmts.jpg)
1st Escalator Board/2-Floors Escalator
(https://i.imgur.com/J13O2WN.jpg)
Round 5/Moose Board/Strawberry Board
(https://i.imgur.com/b9aoXO2.jpg)
Prize Potential:
#1 2000pts.
#2 4000pts.
#3 8000pts.
#4 15000pts.
Notes: The Wall Outline is only a visual tool to be used for clarity and accuracy. Beginning with Round 3, no Round begins with any wall built. First appearance of the Moose, the second fastest animal in Zoo Keeper, worth 4000pts. if captured at Round's end. Board spawns a mix of Elephants, Snakes, Camels, Rhinos, and Moose. Zeke builds wall in four-brick layers.
Round 6/30K Lion Board/Trophy Board
(https://i.imgur.com/kF7iODH.jpg)
Prize Potential:
#1 3000pts.
#2 6000pts.
#3 12000pts.
#4 25000pts.
Notes: First appearance of the Lion, the fastest animal in Zoo Keeper, worth 30000pts. (on this board only) if captured at Round's end. Board spawns a mix of Elephants, Snakes, Camels, Rhinos, Moose, and Lions. Zeke builds wall in four-brick layers.
3rd Coconut Board/Blue Coconut Board
(https://i.imgur.com/xhXE1TO.jpg)
(https://i.imgur.com/Aw7T5WA.jpg)
2nd Escalator Board/3-Floors Escalator
(https://i.imgur.com/o29FoSr.jpg)
(BEGINNING OF LOOP)
Round 7/40K Lion Board/Money Board
(https://i.imgur.com/ACduBEi.jpg)
Prize Potential:
#1 5000pts.
#2 10000pts.
#3 20000pts.
#4 40000pts.
Notes: Lions captured at Round's end are worth 40000pts. Board spawns a mix of all animals. Zeke builds wall in five-brick layers, so only two passes over the same area are required for the wall to reach maximum thickness.
Round 8/50K Lion Board/Rainbow Board
(https://i.imgur.com/t6q6x0v.jpg)
Prize Potential:
#1 8000pts.
#2 15000pts.
#3 30000pts.
#4 60000pts.
Notes: Lions captured at Round's end are worth 50000pts.Board spawns a mix of all animals. Zeke builds wall in five-brick layers.
4th Coconut Board/Red Coconut Board
(https://i.imgur.com/jmW3SmE.jpg)
(https://i.imgur.com/9ghp5qw.jpg)
3rd Escalator Board/4-Floors Escalator #1
(https://i.imgur.com/4d69qEk.jpg)
Round 9/60K Lion Board/Green 4-Net Board
(https://i.imgur.com/lsNJ20j.jpg)
Prize Potential:
#1 10000pts.
#2 20000pts.
#3 40000pts.
#4 80000pts.
Notes: Lions captured at Round's end are worth 60000pts. Board spawns a mix of all animals. Zeke builds wall in six-brick layers.
Round 10/70K Lion Board/Beige 4-Net Board
(https://i.imgur.com/GBaPVzd.jpg)
Prize Potential:
#1 15000pts.
#2 30000pts.
#3 60000pts.
#4 120000pts.
Notes: Lions captured at Round's end are worth 70000pts. Board spawns a mix of all animals. Zeke builds wall in six-brick layers.
5tttp:h Coconut Board/Invisible Coconut Board
(https://i.imgur.com/yeLe2ko.jpg)
(https://i.imgur.com/2UbkDRu.jpg)
4th Escalator Board/4-floors Escalator #2
(https://i.imgur.com/4d69qEk.jpg)
Notes: 4-floors Escalator #1 and #2 are identical in terms of gameplay, they simply fall at different times in the loop.
(END OF LOOP)
After completion of the 4th Escalator board, the game enters a loop that begins with Round 7 and ends again at the 4-floors Escalator #2. However, Round 7 now becomes Round 11, Round 8 becomes Round 12 etc.. And the Round counter ticks up until Round 19, after which it resets to Round 10. This reset of the Round counter occurs the fourth time the Rainbow board is encountered. More importantly, as more and more Rounds are completed, the overall speed of animals continues to increase. Precisely, the animal speed counter increments by one after every loop completion and increments by one for every Round within the loop - e.g. if the animal speed counter is at 39 for Round 7, it will be at speed 42 for Round 10, but back to speed 40 for Round 11. Note: Round speed increases have no effect on the Escalator boards.
[EDIT] A better way of explaining the speed increase is to say: every loop, each Round type increases in speed by 1.
As to what that increment means or how much it impacts the game, I don't know. I do know the speed scale is limited to 99, but I don't know where it starts. Someone will help me with this [EDIT] --> See response to this edit here: https://donkeykongforum.net/index.php?topic=772.msg12826#msg12826 (https://donkeykongforum.net/index.php?topic=772.msg12826#msg12826)
Strategy
Coconut Board (General):
There is no one correct way of playing the non-Invisible Coconut boards. Try and be quick to the top, as any delays will only allow the monkey to throw more coconuts on the screen. The monkey will only stop throwing coconuts once the screen is completely saturated to the point of causing slow-down.
It's technically possible to dick around forever on these boards, although I've yet to see video of someone exploit this tactic to a score of any significance. The inclusion of the landing points and prize points figures was likely unnecessary, but in case someone wants to investigate Coconut board exploitation, I documented all point sources for thoroughness. Twin Galaxies had a rule in place to prevent unlimited top-platform landings, but it is my opinion that such a rule is irrelevant. As I said, I've never seen this tactic exploited to a point where it could even begin to threaten the top "normal" gameplay scores, and so, until someone demonstrates Coconut leaching as a viable point-pressing tactic, I'm going to assume it is not.
Coconut Board (Invisible):
To consistently pass the Invisible Coconut board with ease, players must develop a patterned approach. All Coconut boards actually begin with the same sequence of platforms on levels 1 through 4, and several patterns exist which can take advantage of this. If the pattern is missed, sometimes prizes will show the location of platforms, although no prizes spawn on the 5th platform so its location can never be seen.
For further discussion of the Invisible Coconuts, see here: https://donkeykongforum.net/index.php?topic=772.msg12826#msg12826 (https://donkeykongforum.net/index.php?topic=772.msg12826#msg12826)
Escalator Board:
The Escalator boards always exhibit the exact same behavior and are 100% patternable. Nevertheless, the Escalator boards can be some of the most challenging and frustrating boards in the game. Most players will learn systems to clear the 1st-floor and 2nd-floor escalators without trouble, but all players will have difficulty clearing the 3rd-floor and 4th -floor escalators until they have practiced them extensively.
The challenge in clearing the 3rd-floor and 4th -floor escalators is not in recognizing the animal patterns, but in jumping over the cages blocking the escalators before the animal patterns break down, and a continuous, unsurvivable stream of animals comes parading from the cage.
These so-called "bonus stages" can easily eat more lives than they reward, and it is not at all uncommon for newer players to lose all their remaining lives the first time they encounter the 4th-floor of the Escalator board.
Practice, practice, practice.
Rounds (General):
Save walling in the animals until near the end of the Round. In later Rounds it becomes impossible to keep the animals walled from the beginning of the board through the duration of the timer fuse; i.e. the animals move too quickly and will expeditiously destroy the wall. For this reason, it's actually better to let the animals out intentionally, but in a way that can be controlled.
The Golden Rule: Upon reaching the wall perimeter, all animals must travel around the perimeter the furthest distance possible to reach Zeke. e.g. if Zeke is positioned in the top-middle of the wall perimeter and an animal exits to his right, that animal will begin traveling clockwise around the perimeter; and if an animal exits to Zeke's left, that animal will begin traveling counter-clockwise around the perimeter.
(https://i.imgur.com/yObjxEm.jpg)
(The fella from the College Humor video who talked about animals traveling to 6 O'clock when Zeke is at 12 O'clock actually did have it right.)
To manipulate animal behavior using the Golden Rule players must be careful to watch where Zeke's position is relative to an animal exiting the wall: a task made easiest through deliberate partial wall building.
The following videos demonstrate how partial wall building and deliberate positioning of Zeke are used to control the direction animals travel after exiting the wall:
Video#1: https://www.twitch.tv/videos/45945011?filter=highlights&sort=time
Video #1 shows one method for controlling the direction of animals on a Rainbow board.
This is a "bottom-open" strategy, and while "top-open" strategies can be just as useful, "bottom-open" is surely the most commonly employed by Zoo Keeper players.
Top-Open Strategy Shown on 70K Lion Board:
(https://i.imgur.com/HC8ngId.jpg)
In Video #1, the first net is used to reverse all the animals and complete the right side of the wall, which ensures the animals will most readily exit through the bottom of the wall and thus be forced to travel clockwise around the perimeter. After reversal of the animals I want to hold my position in the lower right corner until the last animal exits the wall. In this case, the last animal is an annoying elephant which refuses to exit, and I am forced to bail out across the bottom before it reaches the perimeter (It is important to continuously jump when crossing areas of the perimeter where brick should not be laid - as long as Zeke is jumping, he will not lay wall brick). Luckily, by the time the elephant finally makes its way out I have made it back to a position which forces the elephant to join the common direction of the pack.
Video #2: https://www.twitch.tv/videos/45944852?filter=highlights&sort=time
Video #2 shows one method for controlling the direction of animals on a 60K Lion board.
Again, the 1st net is used to reverse the animals and the last net is used to capture them. Nets #2 and #3 can be used to either cage stragglers traveling opposite the pack, reverse the pack, or try for big jumps (Zeke is invincible so long as he holds a net). In this case, I used net #2 to claim a million point jump and net #3 to reverse the animals in hopes of regrouping them. The grouping of animals using the nets will be discussed in the advanced section of Rounds strategy.
Rounds (Advanced; AKA: The One Hundred Million Point March):
There is a maximum number of animals (16) that will spawn on any Round, and because Zeke's position is directly linked to the direction animals travel after reaching the wall perimeter it is imperative to know when exactly that 16th animal exits the cage in the board's center. The following image gives a close estimate to when the 16th animal exits on each of Rounds 7 through 10.
(https://i.imgur.com/v8XeA8G.jpg)
[EDIT] The varying markers of last animal exit are indicative of the real time length of each Round's timer. I haven't checked this, but it's quite possible the last animal exits at the same real time on each Round- i.e. the 70K Lion board is the longest in the game.[EDIT] Armed with this information it becomes a lot easier to know when it is safe to move freely around the entire perimeter.
For further discussion of the timer fuse, see here: https://donkeykongforum.net/index.php?topic=772.msg12826#msg12826 (https://donkeykongforum.net/index.php?topic=772.msg12826#msg12826)
Chaining Nets Together
Once comfortable with general Round survival strategy, it is time to investigate the assorted methods of forging large, jumpable groups of animals.
Jumping large groups of animals is the most efficient way to score in Zoo Keeper. In fact, jumping large groups of animals is so scoring efficient, all other sources of points within the game become marginalized in comparison. Capturing the Lions can yield big points, but just about every other animal isn't worth squat.
Points for Captured Animals
(https://i.imgur.com/ydkEx8Q.jpg)
Points for Jumps
(https://i.imgur.com/dENfWKm.jpg)
Video #3: https://www.twitch.tv/videos/45869565?filter=highlights&sort=time
Video #3 shows one method for creating a large grouping of animals on a Money board.
In this example, grabbing of the first net is delayed so that the last net can be snatched up immediately after the first expires, and a big jump can be tried safely - the last net is used here as a "safety net" ;)
Video #4: https://www.twitch.tv/videos/45985671?filter=highlights&sort=time
Video #4 shows one method for creating a large grouping of animals on a 70K Lion board.
This is essentially the same method demonstrated in Video #3, but here nets #2 and #3 are used to set up the big jump try.
Of course, these schemes will not always work because there is no way to influence which particular mix of animals spawn on any of the mixed animal Rounds, nor is there a fixed speed for any species of animal. i.e. sometimes a board will spawn three extremely slow elephants and four extremely fast lions, while other times, the same board will spawn one fast elephant and six lions all moving at different speeds. Furthermore, even with the right mix of animals there can be no guarantee the distinct animal positions will blissfully coincide with when Zeke needs to grab the net for setting up a big jump try. For these reasons, Zoo Keeper becomes a game of decision making more than anything else. Players may recognize a situation where a net can be used to forge a tight grouping of animals, but there may be no "safety net" to help claim the jump; is it worth the risk? Similarly, situations will arise wherein delaying a net in trying to set up a big jump try will just be too dangerous, and a decision of survival versus points must be made.
Evaluation of risk versus reward is everything in Zoo Keeper.
For a discussion of Round scoring average and the trade-off between actively hunting big jumps and playing safely, see here: https://donkeykongforum.net/index.php?topic=772.msg12925#msg12925 (https://donkeykongforum.net/index.php?topic=772.msg12925#msg12925)
A Good Mix of Animals (AKA: Not an Elephant in Sight)
(https://i.imgur.com/5wxBcZb.jpg)
Interestingly, the one time I managed a 30 million jump (from a ROUND 10 savestate) I had to "raw dog" it. After their capture most of the animals - especially the Lions - re-exit the wall very quickly, and subsequently there is little time to reach the grouped animals for a big jump try before the faster animals break off from the pack. However, there is an alternative to trying for a big jump immediately after the animals respawn. Instead, the faster animals can be allowed to break from the pack and the big jump try is taken once the pack of faster animals has circled the wall once and rejoined the pack of slower animals. Depending on how the board was played up to that point will determine whether or not a "safety net" is in place. In the following examples I had no "safety net" and was forced to "raw dog" it with varying success.
Video #5: https://www.twitch.tv/videos/46001032?filter=highlights&sort=time
Video #5 shows a big jump try based on the merging of two distinct groups of animals.
Video #6: https://www.twitch.tv/videos/46001020?filter=highlights&sort=time
Video #6 demonstrates the same technique as shown in Video #5, but with less success.
Finally, the methods shown here are but a few of the many possible ways to play the Rounds. For example, the methods demonstrated in Videos #1 and #2 can be employed in reverse, to create a "top-open" wall; and, the methods demonstrated in Videos #3 and #4 can be applied to numerous other pairings of nets. The methods shared here may not even be the most effective, and therefore, players are urged to investigate these matters for themselves, and make this game their own.