Thank you for the review!
There's already a restart level button right now, but I suppose it isn't in a very obvious place. Pressing escape will bring up a pause menu where you can restart the level.
We had also planned on adding a number of other items that gave different abilities, such as being able to pick up boxes (allowing you to pick up boxes out of stuck corners and even out of pits), being able to smash boxes, possibly some abilities that mess with visibility (one character holds a flashlight while the other navigates a maze and pushes boxes), and maybe 'tier two' abilities that manipulate how many boxes you can push or lets you push metal boxes. We would design the puzzles in such a way that deciding which character got which ability was actually part of the puzzle, but we didn't have quite enough time to do that.