You "clip"/ go through the ramps which is a bit weird, they should be solid items. Also you should put a shadow texture for the player character (As of now you only have shadows for items.
Of course there needs to be more thing to do in it but that's a no brainier.
-Ability to make boats
-Maybe add islands you can go to
-Add different types of fish you can catch
-Maybe have random generator for what type of shark will attack you (IE: Sand Tiger Shark, Hammerhead Shark, Thresher Shark and ETC)
-More plants (Wheat, Corn, and ETC)
-Bigger farm beds
-Crates (Bigger storage)
-Bow and arrow
-possibly of flooding on the raft where the shark can get onto the raft
-Rain/ weather system
as of now that's all I can think about.
Do you guys think any of these would be cool?