Wario Land: Super Mario Land 3 is the thinking man's Mario. One of the better platformers I've played on the Gameboy due to the deliberately slow movement with more of a focus on discovery than getting to the end of the level. The game has some crusty controls but great level design and an implementation of RNG in certain areas that ties the theme of 'a game about Wario' impressively well into its mechanics. This game really makes you feel like a Wario - misgivings, crust, and all.