It is a full out Operating System for SB, you can customize almost everything, it's basically Windows 7 SB, and I don't know the key, but it is called Alpha OS 4.0. It is in Japanese
If it was a 3D game, that idea wouldn't be possible, and their is no way to put Gang Beasts in a 2D perspective. So technically, it is impossible to make a Gang Beasts style game.