Thanks for your review.
I'm not sure what you would want to happen if there is no gravity. Without it the shapes would just be sitting there and there would be no need to go fast. It's true that now you will score points if you do nothing 25% of the time, but it is still in your best interest to speed up the shapes that need to go down because you only have 1 minute to score points.
Regarding the color blind stuff: A friend of mine is colorblind so I kept that in mind. The code was built in such a way that I could select different kinds of palettes for each kind of color blindness. But since I never managed to finish the level that would have 8 different collectors I never needed to implement it.
Touch controls should just work I think. The biggest problem with playing on a phone is the aspect ratio. I made the game square and that means that on a phone you will not see a lot of the level. UI is always a problem for me :P