Hey!
You have the core mechanics for a platformer game set up, i suggest adding basic effects which would drastically improve the game if you plan on keep developing it . always try to finish your projects even after the jam, its good practice.
Some things you can add:
- Music and sounds effects for moving/jumping
- a Dash you can use even in mid-air, will give you more level design option on distanced platforms
- Idle and Jumping animations - there are a lot of predefined animations available in itch for free, you can download and use those as a reference