Puzznic (パズニック Pazunikku) is a tile-matching puzzle arcade game developed and produced by Taito in 1989 and was ported to the Nintendo Entertainment System, Game Boy, PC Engine, Sharp X68000, Commodore Amiga, Atari ST, Amstrad CPC, Commodore 64, MS-DOS and ZX Spectrum between 1990 and 1991. More information on Wikipedia.

A trainer offers one or more cheats like unlimited lives, invincibility, more ammo etc. Because this is done during runtime a trainer is not to be confused with a savegame editor.