How to Play Local Co-Op on PC
First, launch the game in big picture mode. Once in the game go to options, button mapping, keyboard settings. Now open up the steam overlay and go to configure controller. Basically you just bind player two and three controllers to what the controls for the keyboard are. The first player controller does not need to do this, but the second and third controllers need to. Make sure you save the controller bindings on steam, because you cannot play vs local battle this way, because technically everyone is “player one”, so if you want to play vs local battle just open up the steam overlay, go back to configure controller, and use the recommended controller binding. Now three people can play together, on the same team. Technically everyone can control all the fighters, so just let the people you are playing with know that, so then they can start playing when they are tagged in. We hope this helps anyone who wanted to play local coop with their friends and family.