Impressively expansive for a jam game! The grapple was a lot of fun to master, though it felt like at around 10 or so grapple charges the limit started to become basically irrelevant and at that point it made traversal a lot less interesting - I found it to start getting a little tedious towards the end which was kind of disappointing. It also allowed you to pretty easily skip past some of the more specific item gates - I ended up never really getting a chance to use the umbrella in particular, despite it looking pretty neat. I also ended up skipping the intended gate for the bubble blower, but that ability was still a lot of fun to use for general traversal after getting it so that one didn't feel as disappointing.
I had an issue where the gameplay sound completely cut out a short ways into the game - the menu sounds still worked fine so the game was clearly still able to produce sound, but the actual game turned completely silent. Was disappointing as I'd really liked the sound design up until that point, and the rest of the game ended up awkwardly silent. Were there a saving system it probably wouldn't have been a big deal as I bet it'd be easy to fix by restarting, but I didn't want to lose my progress to do that. I think the music also cut out even sooner, as I didn't hear any music after the main menu at all.
The visuals weren't the most refined, but they're coherent and create a pretty appealing world. I like the parallax backgrounds and the slime characters, they're very charming. Writing was also very charming and again impressive to have so much of it in a jam game.
With the lack of saving it's really annoying that the ending just boots you out to the menu, I might've liked to go back and try to grab a couple of the items I missed.
Overall, very good game, very strong contender for this jam. Good work!