lol didn’t even realize @Polygonzo already got Dynamite Headdy. I’m gonna edit this as a replacement and as an apology.
Thinking about the ideal bonus stage. Donkey Kong Country and Crash Bandicoot have ones that aren’t too distinguishable from the standard level’s gameplay so I haven’t included them. Also, are there cool bonus stages in non-linear games? There must be though it’s definitely more common in linear ones. In the Japanese version of Chameleon Twist you can hunt down carrots to give to the White Rabbit to play pool and bowl. I don’t know if that really counts but since it’s such a novelty within the game it feels like a bonus stage to me.
the sonic 3 special stages are so confusing because the surface is presented as if it has positive (ballooning) curvature everywhere, yet there is no possible way to wrap a large square checkerboard around a sphere. the only way it makes sense is if we are just being shown a positively curved section of a more elaborate shape, which has negative (pinched) curvature elsewhere.
if you were to fully zoom out the stage it would actually have to look something like this:
Crash Bandicoot is interesting because the floating levels are how you save the game and if you die on those, you can’t save. They also beg you to risk death by being filled with boxes over empty space.
I’m counting the Chao World and you can’t stop me:
You may know of it already but if not, Cameltry is essentially more of this. There are quite a few levels/gimmicks mixed in across its different versions but the quirkiness and surreal mystical aesthetic of the original made it my fav version