Same issue. Mouse cursor is working, animation too but nothing else. Only Alt+F4 to exit game. And yes, I tried every key on keyboard.
When I press spacebar od Enter, yellow guy runs in, fall down, stand and then keeps running on same spot.
Windows 10 x64 CZ, I7 6700K, GTX 1070, 1440p resolution.
I will try it on another PCs later.