Family 4 — "can the player act?" This is the rung that turns a demo into a game. Read the pad, move something with it, then branch out to the SNES's exotic controllers. The console auto-reads every input device each VBlank; you just read the result.

The ladder

Rung	Example	Developer question
4.1	controller	How do I read a joypad — held vs just-pressed?
4.2	move_sprite	How do I drive a sprite with the pad?
4.3	two_players	How do I read two players independently?
4.4	mouse	How do I read the SNES Mouse?
4.5	superscope	How do I read the Super Scope light gun?

The idea in one screen

padHeld(0) returns a 16-bit bitmask of the buttons held this frame; padPressed(0) returns only those newly pressed (edge detection — without it, a single tap registers dozens of times at 60 Hz). Act on the bits, and for movement push the result to a sprite with oamSetXY.

Bit: 15 14 13 12 11 10 9 8 7 6 5 4

B Y Sel Sta Up Dn Lt Rt A X L R

The mouse and Super Scope are read the same way after a device-ID check; the Super Scope lives on port 2 and latches its aim from the PPU's H/V counters.

Start at 4.1 to read the pad, then 4.2 to feel a sprite respond to it — that's the moment it becomes a game.

Controller Input SNES Mouse Drive a sprite with the pad Super Scope Two Players Example