Design controls for the hand — ergonomics, mapping, and button economy

Play is physical: the player's fingers, not their conscious mind, execute most actions once learned, so the layout of controls shapes how the game feels to operate [S-hodent-gamers-brain]. Frequent actions on awkward inputs cause constant friction and error; conflicting or overloaded bindings break the muscle memory that skilled play depends on. Button economy is real — a controller has a fixed, small number of comfortable inputs, so each new action costs one, and adding capability often means replacing a binding rather than piling on another (natural mapping and constraint, per Norman [S-norman-doet]). Designing for the hand keeps the interface between intent and action invisible, which is the precondition for good feel (FEEL-0002).