Thanks for the clue!
Just tried other buttons, pretty good idea and nice arts!
I would only advice you(if I may) to make the buttons more visible, cause I saw the aim button, but the bottom buttons left completely unseen by me, that is why I didn't try them on the first go! Maybe give them a light outline, or just make them lighter to contrast with the darker ground?
Anyway, interesting idea, and nice job on the implementation!