Add more levels, maybe an increase in difficulty and you could easily publish this on Steam!
Maybe you could add more items as well. Either way if this game does make a full release I will be looking out for it!
Also another thing I would say if you do make a full release try not to add too many levels where you are just avoiding water like in the last level. It is fun a few times, but personally speaking, I had more fun bouncing off of the walls and that felt more dungeon-esque
Also adding props you would see at a Mini Golf course would be a cool addition but then it begins to lose simplicity, I just thought I would throw the idea out there.
GG