dYoqu can use wasd to control the nightmare cuphead, sans aqand bendy and arrow keys to control boyfriend. You dcadn use 1 to switch to cuphead (or also the green flag), you can use 2 to switch to sans and you can use 3 to switch to bendy. You can also press q and e for some extra stuff
funkipedia link here: https://fridaynightfunking.fandom.com/wiki/Friday_Night_Funkin:_Indie_Cross