The game gets hard really really fast. I'd suggest to flatten the difficulty, by introducting the mechanics one at a time in the first 2-3 levels and make stupidly easy (change color once and you win, change gravity once and you win) and the level selection that require you already knows the control to select the tutorial only allows player to mitakenly not start with the first level (like I did) I'd suggest to force the player into the first simple tutorial levels to get how the game works before allowing them to start the level in any order.