imagine playing on a laptop with a trackpad.. You can either use your trackpad left-handed or cross your hands over to use the arrows with your left and the mouse with your right. Neither of which is very comfortable. There also doesn't appear to be any directional information coming from the mouse, so do you need to tie actions to clicking rather than keys? Especially as tying blocking to right click makes it very hard to use on macs, where right clicking is not particularly game-friendly.