A Boy and His Dog is a short puzzle platformer built in 2005 for homebrew PSP. In this game, you guide your dog pal through a level, toggling switches and pressing buttons to create platforms. A development diary written when the game was released is available: http://brightnightgames.com/games.php?game=abahd&sec=development.
See the included ReadMe. The game should install and run on PSPs with any CFW version. Includes a build for CFW 1.50, though you will probably want to use the 1.00 version, which should work in all other CFW versions. The 1.00 version also runs well in the PPSSPP emulator.