I think if there was a menu button in the corner, I would have clicked it > and maybe could have rediscovered the controls I missed, like if there's a button labeled "Restart At Checkpoint [T]", or just a general list of controls in a permanent place I can refer to.
I missed that you mentioned it in the description, whoops! I was in fullscreen mode and felt locked in cus when the game is minimized, the itchio page cuts off a big part of the screen, so for some reason minimizing never crossed my mind!
(Like the start game button is cut off completely until you fullscreen it)