I made it to level 6 and then it just crashed. It was fun, but controls are too floaty making the platforming a bit hard and the long delay when switching characters made me often wonder if it was working at all.
There is also a few collision bugs with the ceilings, in which sometimes I could just jump through the ceiling, bypassing parts of the levels. Also the music was a bit annoying, as the whole game used that same short loop of music for every level and the selection screen.
That's all I can think of. Wish you luck!