GUYS! You can fall off the map and press Esc and you will freeze mid-air until you try to grapple, try it! With this you can grapple and swing between levels since it's all just one map and not seperate. You can toggle with A and D between levels so that you can see where you are swinging.
(The level select rectangle is solid and it can be grabbed but note that when you toggle between levels that rectangle disappears and reappears in the next level so if you are grabbing it, it will let go when it disappears)
Edit 1: Also thats how you can do the last level so I think this is also intentional
Edit 2: Wait what the hell? There's a secret level with tens of yellow and green stickmans floating??
Edit 3: I wish our Blue guys could spawn there as well when we press R and interact with the floting guys... I'm having way too much fun with this game and I wonder if there is more