Thanks for the rich feedback! We're also having collision issues haha It'll be completely remade after the rating period. Now, about the game design decisions, yeah, they are really hard to make, that's why your feedback is so important. Since we are probably porting it to mobile and creating a "mobile first" design, the button's functions and layout are going to solve this problem. For the Web version I don't see any problem in using the mouse wheel or unlock the ability to use a button to change the crystal.