There’s plenty of fun platformers, puzzlers, action games, and arcade ports on portable systems like the Game Boy and Nintendo DS etc. Nintendo has always been a master of “pick and up and play”-ability.

Some classics include the Super Mario Land and Wario Land series, Kirby, Donkey Kong GB (it’s the original arcade game plus a brilliant puzzle platformer), and the Zelda titles. There’s even some lighter weight RPGs like the Pokémon games etc.

There’s also Game Boy ports of the Game & Watch titles which are great short time wasters - Game Boy Gallery and Game & Watch Gallery series.