Hey! Nice game, I see that it has big potential. Few of my thoughts:
1) It is really hard to match the colors. Especially yellow and orange.
2) I am not sure that random color selection is a good choice here - I spent half my time standing in the corner and shooting floor just to get the right color. It seems that it would be better if I can select needed color and if there will be something (some new enemy) that won't let me just stand on one place. This way I will have to move all the time, trying not to die and match the right colors.
3) I managed to shoot out the balls out of bounds. Just fyi.