You don't use brackets on the first level, you have to push a slime in the pit so you can walk over it.
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Went back to play the level based on this information and was able to clear it no issues. I think the concept of getting powers from others to use for puzzles is a good idea that I could see being pushed further! My confusion with pushing the slimes was that I didn't realize that one bit in the first level was meant to be a slime that had fallen in (walking over it places the asset on top of the character, so I had thought it was something else) along with the fact that you want to avoid touching the slimes as they deal damage. Nice work!