Fun game, but you can easily break the 2 player mode if white presses all 4 arrow keys at once in a very specific order, which will result in the white player always moving left and the black player not being able to control the game anymore.
I tried, but for some reason my controller wasn't working, idk
Is the game looking specifically for controller 1 and 2? Because if so, I would maybe recommend that you create a little screen saying like "player 1, press any button" or something like that, so that the controller doesn't have to be connected as controller 1.