The Sega Teamplayer is a
multiplayer adapter for the
Sega Genesis that allows four players with four
controllers to play a single
video game (in the tradition of the
NES Satellite). Note that this is not the
Electronic Arts 4 Way Play which essentially performed the same function, only with
Electronic Arts games.
Sega and
Electronic Arts fought long and hard over their respective
multiplayer adapters and which one would be the official
Sega Genesis multiplayer adapter.
The following games support the Sega Teamplayer:
Game list from http://www.emuitalia.com/ages/compat.html