- use different types of presses, such as short vs long press (But bear in mind that distinguishing these inputs can make gameplay difficult, and you should use visual or auditory indicators to help the player understand what is going on)
Consider the effects of double clicking, or tapping a key rather than holding it. Even one button can effectively take on 5+ inputs: tap (1-5 frames), hold1(5->8 frames), hold2 (8+frames), doubleTap(two 'tap' within 20 frames), tripletap(three 'tap' within 30 frames) etc. You should think of 3 buttons as 15, it's too many rather than too few.