Twin Maze is yet another game by Haroldo Pinheiro, which is unfortunately not yet complete. It was intended to make it a simultaneous two player first person maze game, with competitive modes (deathmatch and race) and cooperative modes (vs monsters). Due to the authors time constraints, though, it is, for now, more of an unoptimized tech demo where two players can explore a maze simultaneously. There’s currently no other objectives other than that.

http://www.smspower.org/forums/15979-CodingCompetition2016TwinMazeByHaroldoop