Micro Machines (NES)

Smiley Test
All known NES games from Codemasters (this, Bee 52, Big Nose Freaks Out, Big Nose the Caveman, Dizzy The Adventurer, Fire Hawk, Linus Spacehead's Cosmic Crusade, MiG 29: Soviet Fighter, Quattro Adventure, Quattro Arcade, Quattro Sports, Stunt Kids, The Fantastic Adventures of Dizzy, and Ultimate Stuntman) are based on the same stub library. As a result, all of these games, including game collection versions, include a "smiley test" of PRG ROM integrity and CHR RAM consistency.

To trigger the PRG test, hold Up + Down + Left + Right + A + Select + Start and press Reset. The CHR test is triggered almost the same way, except hold B instead of A. If the PRG checksum matches with internal value or the CHR RAM chip has no bad cells, the program will display a green smiling pixel face; otherwise, it will display a red crying pixel face.