I'm sure jumping from the cieling and flipping the character were on the to do list.
What if you had the gravity changing ability be a power up item you have to go find at first. Often players appreciate having abilities more when they've experienced some time without the ability.
While this game jam asked us to make the majority of assets ( sound/images), most jams allow for use of free to use premade assets,
this page has lots of links to free tools and assets https://itch.io/jam/goedware-game-jam-zero-ui/topic/3759023/free-gamedev-resourc...