Hey, first of all, I just want say, this is awesome and really fun!
One thing that bothered me while playing is that the inventory had a few quirks and was a bit random.
1. Sometimes, when picking up new items, they would go into a different slot. So I would have two of the same items, taking up two slots instead of one.
2. The inventory resizes randomly and hides items that I haven't picked up in a while (which is fine, as long as there is some way for me to see EVERY item that I currently have).
3. Would be awesome if you added some buildable chest or backpack to hold items while you don't need them. I didn't really need the seaweed as well as the farming tools (mainly because I wanted to do the farming later) and I had to throw items as far in the sea as I could so that I wouldn't pick them up accidentally/take up too much space in inventory.