I'm starting to really like Jr., even though I didn't enjoy it so much at first. (I was expecting that to happen though, I've learned over time that I don't really start forming an attachment to *any* of these games until I've dug a groove in my brain for them and am good enough to feel a certain degree of power/control over them.)
Some random thoughts:
Vines and hideout are basically a gimme when you figure them out. Once you know when to wait for the snappers to get out of your way (vines), and when, how, and which sparks to pop with the apples (hideout), it's almost impossible to die on those boards unless you screw up.
I dislike the springboard screens. A lot. Missing the superjump is obnoxious and (apparently) random, and even though I basically know what to do about the birds at the top, they're still a pain in the butt and everything is too "tight" and stressful. Boo.
The keys board is really, really cool and is the real victory of the game's design. It's hard, probably consistently harder than anything in any of the DK games including D2K, but it's hard in a "fair" way. I really like that when you die on one of those boards it's almost always your fault (ie, you weren't paying enough attention, got impatient, etc.) A far cry from the merciless assassinations you have to regularly put up with in DK. Of course, maybe my opinion of this "fairness" will change once I get further than L4.
Making all of this harder on my machine is the fact that I have the elusive "P-kit" romset. The main differences are that the birds on both the springboard and chains fly one "notch" lower than they do on the standard romset. This one seemingly minor difference makes both boards a lot more challenging (at my current level of skill at least, maybe a better player would feel otherwise).
You have to hold the chain lower on the springboard screen when you're waiting to cross over to the safe area, which means it takes you longer to climb up, which means that you can get "egged" if you get bum-rushed by an eggdropper. So you have to look up at the "bird spacing" and be more discriminating about crossing before you do anything.
On keys, there is NO safe spot in the top flightpath area. When you combine that with the fact that the birds can go lower on their initial descent, getting the rightmost key in place can be a real bitch. You're almost forced to save it for last.
I also have a sense that the birds (and possibly the snappers) on the P-kit "seek" you in a way that they don't on the standard ROM. When I'm climbing up, they always seem to try to descend lower. When I stay still, they're more apt to take the upper flightpaths.
The good thing about the P-kit is that it makes the standard version feel a lot easier when I play it in MAME. It's kind of like getting used to running with a weight-vest!
I really want to get this kit to the MAME developers somehow so that all of you (and everybody else in gaming-land) can try it. But I can't justify buying an EPROM reader just to do that one thing. They're bizarrely expensive (hundreds of dollars). It would be cool if I eventually managed to killscreen this version. I couldn't submit it to TG, but I'd be the first, so what the heck!
I've now just barely missed 100K. I will definitely cross it soon.