Thank you for your message, the unlocked key is Shift (for a dash to pass the grids). the checkpoints will have an appearance in a future version of the game (which we improve after the game jam), I personally thought of a cool mechanic idea and an animation related to the fact that the character looks like a will-o'-the-wisp and allowing to have a respawn which does not "break the 4th wall" but I still have to discuss it with my teammate.