Fun game, I get what you mean about the last level. The gravity switching mechanic was enjoyable and I liked the art, especially the player character and menus. Very impressive for only 3 days of development.
I think I would have preferred more agency around when the gravity flips because sometimes I'd be waiting for the timer with nothing else to do. As you do say in the description, some of the mechanics are underbaked but I still think you have made an enjoyable game with the time available. I'd have liked to see more levels which utilised the time freeze mechanic for example :)