For awhile I wondered. Why do some people who are great at shooter games have problems with DK3. After playing a decent amount of shooter games over the past two years, I think I figured out the answer. There are two main things that are different from 95% of shooter games.
1) Invincible enemies that are on the screen for the entire level, level after level. 95% all shooter games seem to have enemies that can be killed, and even if there is an invincible enemy that enemy doesn't stay on screen the entire level. I think for many the fact you can't kill donkey kong, and you can't kill the worms mentally blocks them from succeeding in the game.
2) There is no vanish/invincibility/bomb button that basically makes your character safe for a few seconds. Yes, there is a super spray, but for two of three levels that super spray is very hard to get to. It can be gotten, but no without great risk to your life to get it. For me, for games that have this button, I tend to really struggle with the game because I am always a split second too late in pressing the button to save myself. So a game like 1942 is a game that's near impossible for me to do decent in.
Of course there are five percent of games that do have these two things. One that comes to mind is Robotron.