I tried out Castle of Illusion today, and god was it AMAZING. Thanks for the tip Ack. This game rocks.
I start out the game, and I notice right away that Mickey is kind of slow. I'm like "ok, this will probably suck cause it will be a platformer about pressing jump exactly where the level designer wanted you to, and not a game about
flow".
I use bold for flow, because I think it's the most important part of a 2D platformer.
And then I jump on an enemy and I notice that I get pushed very high in the sky. And I'm like "omg this is great". The game's flow isn't about momentum like Sonic and Donkey Kong Country, it's about chaining enemy jump kills to propel you to even greater heights. This is an amazing simple gameplay idea.
And in my opinion, every GREAT 2D platform game should have some basic fun mechanics that can be used in many creative situations to solve different problems. And this method of movement for Mickey IS such a mechanic. Playing through the levels I noticed that the enemies are always strategically placed when there is a ledge to get to, or a hidden star (health power up), or a secret path which leads to bonuses.
This adds a risk and reward parameter in the game, because this move can be risky if there are bottomless pits below you, but the rewards you get are worth the risk.
Even the duck down move finds a use during a boss fight. This game manages to have only 3-4 moves and does soooooooooo much with it.
I really liked some sudden surprises too, like when I climbed to the top of one of the toy land stages, got the key, and then had a fun way down (not spoiling it for anyone who hasn't played it, I was very pleasantly surprised by it

)
The only negative thing I can think of, is that with so much of Disney's and Mickey's old cartoons they could tap for level environments, they go with pretty generic stuff. There are some fun twists here and there, but I know that a stage based on steamboat willy would have been just so much more fun than "forest", "cliff", "toyland".
But that really is nit picking. I'd highly recommend this game to any platformer fun.
Just be warned that it does grow some teeth after the first few levels. Though I think I'll be able to beat it around the 3rd or 4th time I try.