Hi again! I don't want to ask for too much, but maybe you could add a few UI arrows? Hands look out of place here, actually. 
Hi! No problem. Pixel art is the most easiest thing to increase resolution. In graphical programs you can just scale it flawlessly with the method nearest neighbor. In my game engine - Godot you just need to choose the right import option in settings. I guess Unity also should have something like this. After that you just need to use right scalable object in your editor. I am sorry that I can't help better, I don't know Unity specifics. And English is also no my native language😁