yes there are, there is unk3 (sega genesis version), mk2, mkt, mkg, ect, im curently using umk3 (sega genesis version) on my computer and im playing with my friends but you need a progam called hamachi that allows you to play online because the game alone it has the option to play online but it dosent conect to onther computer if you dont have the hamachi program, if you download tha umk3 game and the program lets play sometime