Hey there. This is an excellent PC game. I have some wonderful news - the game isn't just compatible with Xbox controllers. It has a friendly relationship with JoyToKey, which means it's actually compatible with hundreds of controllers, including N64 ones.
It's a little bit annoying that the menu navigation controls are "Arrows and Enter" rather than "WASD and Space" - that would've allowed a better separation of the player controls. Nevertheless, a Player 1 controller can include both arrows and WASD, as long as they're separate. Here's the optimal control list I came up with:
