One point I have already received is that user's don't know how to play when they first go in. There is a help button on the title screen '?' that explains how to play.
Thanks for taking a look!
I've been a long time viewer but first time registered user. Looks like I cannot post a link to the game quite yet. If you want to give it a try, just search for 'Gradient Sense' in Google Play and it should be the first app.