Checking it out now! Initially, I'd offer the advice that with jams it can be much easier to get traffic with games that run in browser. I did the 2020.2 Jam with only a windows download and it really limited the feedback I got compared to doing webGL this time around!
From playing it, I would say that instructions on how to change characters, and an indicator of which character is selected would be wonderful! Loved the puzzles and the music is soft and calming.