Micro Mages by Morphcat Games Is a Modern Homebrew NES Cartridge
This is an amazing little project. Micro Mages by Morphcat Games is so tiny that it fits on a 40kb NES cartridge. Getting a game that looks this good on the old-school hardware took an impressive amount of crunching the graphics down with reused sprites.
It can be played solo or up to 4 players. There is a hard mode that can be unlocked. For the retro gamer types, this is a a fully realized dream. Everything is stripped down to put all of the core elements of game design on display.