Above the keyboard there's a switch that you can flip to go from game controller mode to mouse mode. (liliputing.com)
Our advice: sticking between controller mode two and three produced the best results, but it's worth experimenting with the different options to suit your playing style. (teamvvv.com)
You can play with a keyboard, and you can even play in shared controller mode if you only have one device but still want to play multiplayer. (cleverendeavourgames.com)