These MAME games have been selected as being suitable for play using just one-button. They may need some adaptation to be played in that way, such as with the OneSwitch Pulse system, or using custom cheats as with Asteroids.
To find more games, see the main MAME page. N.B.There are no direct links to games here, just ideas and pointers.
Atari's Asteroids can be made one-switch accessible by turning the "One Switch Hyperspace Mode" cheat on (fast recommended) and using Hyperspace (SPACE BAR) as your control
Slow the game down via the Slider Controls > Overclock CPU option (CTRL + arrows) to something like 30%.
Atari's Canyon Bomber is a one-button game (drop bomb) for one or two players.
Optional cheats can give you unlimited bombs. Normally requires excellent timing otherwise.
Konami's Frogger can be made one-switch playable by setting a switch to UP. Using the OneSwitch Pulse system tapping for UP and holding for BACK is possible to give extra control.
I recommend using the Cheats option for "Infinite Time" and if helpful, use the Slider Controls > and Overclock the CPU to around 30%.
Namco's Galaxian needs the OneSwitch Pulse system (use the Space Invaders profile) to make accessible.
Bundra's Neck-N-Neck is a one-switch game for one to six players.
Horse 1: Left Ctrl
Horse 2: Left Alt
Horse 3: Space BAR
Horse 4: Left Shift
Horse 5: Z
Horse 6: X
Outrun can be made oneswitch accessible using the 4Noah utility. Alternatively a system like VRAA could be used or team-play.
A OneSwitch Pulse system is on the to do list.
Taito's match-three (colours) classic, Puzzle Bobble, aka Bust-a-Grove. Useful cheat is to "select help line enabled". This keeps the helping aiming guide on at all times.
LEGAL NOTICE: Many game ROMs remain the copyright of the original owners who may or may not be happy for them to be played under emulation. Put in the context of these games impossible to play in their original format for some disabled gamers and I would hope that attitudes would be more relaxed. Support developers by letting them know why you can't play their games and offer some solutions.