hey man, thanks for playing the game. The bullets can hit the cells you are protecting sometimes when the virus is infecting them, it was sort of intended. The game is about using the B cells to do most the work(The small cells). The shortcuts are like so, M for Menu, R is for restart, P is for pause, T is to show the tutorial page. we made them so players can either use the keys or click on them, just to make them alot easier to use.
Thanks for the great comment tho!