The game is supposed to have checkpoints! The big grey squares with a computer on it should become activated when you are closed to them, and when you press R you restart from them. But maybe it was not working on your platform?
I am using an "azerty" keyboard so I was not sure about zqsd or wasd, and as I recorded a voice saying it was the arrow keys I just left it as is. I will update the game so that both zqsd and wasd work though!
Thanks for trying my game and for the feedback!