Nice idea and an impressive level of polish! I think the character unlocks could be spread out a bit more though. ;) (I don't even know what they are beyond the first one, because I unlocked them all at once.) Also agree with an earlier commenter that there might be a better way to telegraph the timing of the platform, e.g. by having it flash three times before it switches like the red/blue platforms in SMM2's Super Mario World 3D style.