I actually don't mind the changing colors at all, but I agree with other reviewers that some of the losing messages need to go, especially "I did 9/11"! Although they don't affect me personally, you are bound to get hate with messages like that. I didn't notice any delayed sound effects but after the music finishes (my song lol) it is stopped for almost a minute or two before it repeats. Is this to make things less repetitive? Otherwise you could just add more tracks to keep it going.
I like how each level has some unique twist, such as the expanding cube, the bouncing ball, and the one after the bouncing ball level where you have to stay in the black areas. (I haven't gotten past that one). However the bouncing ball level has a glitch - when you move to the bottom you die really fast and it makes the screen flicker until you move directly under the ball. Also, what determines how high the ball bounces? It seemed kind of random to me.
Overall I really enjoy the concept but some things do need to be worked out. This could be good!