A not so good control system...
My main flaw with the game is that it took too long to get familiar with the controls. Nine out of ten times I die is because I accidentaly pressed the wrong button, or pressed it too late. Especially on levels like the boss levels and the beginning of level 12, I want the controls to flow, and not that I have to think about what button to press when I change forms every time.
When you think of it, wouldn't it be better to just give one guy all those powers. There is no extra value at all in the guy constantly having to change forms, except for giving the game some kind of a ''theme''. The platforms where only one of the three forms (colours) can stand on don't give anything positive to the game IMO, since all you need to do for them is remember which of the ''JKL'' keys belongs to which colour.
I'd rather have a game which, after completing it, gives you the idea of having completed some hard but not impossible puzzles, instead of giving the idea that you finally know which key belongs to which colour.
It might be just me who is having trouble with the keys, but after completing a lot of levels, the control scheme has to be completely clear and easy to use in a game.
Apart from that, it's a fine game. The graphics are good, and you tried to make a good and original game. Though it's not completely glitch-less, ( Turning switches while invisible never worked for me, another glitch is on this page, a bit in the middle. Here he walked into walls while transforming on a place where the door normally stands: http://www.newgrounds.com/bbs/topic/1 035978/734 (Remove any spaces)) Overall an good game, but not too easy to play.