Finally got to beating this! I really enjoyed your writing. The characters' personality was able to shine through, and your face edits helped sell the interactions. Reid got a bit weird didn't he? Also Tea, Biscuits, Accessories store? Lol. The few custom tracks sounded nice, but they were interspersed with those super heavy and loud MZ tracks, so the contrast caused some suffering.
For the sake of the jam, my biggest suggestion is that less is more. It was a WIP for sure, but you had a gameplay loop gathering the four shades. There were some distracting irrelevant parts, like shops with items to buy, jumping juice that I never understood where to get or why to get, secret tents and moveable boulders hinting at secrets but leaving nothing. You could definitely note the game will be continued and be a WIP, but curious players will likely explore the unfinished maps and leave with a feeling of being incomplete, whereas if you had ended with the shade possession reveal, you'd have a strong finish.
To sum it up, if you had taken your story and gameplay and concentrated it, removed all the things that didn't matter or got players lost, the product would have been much stronger as a whole.
Hope to see some mighty polish if you keep up with this game!