Well the concept is nice, some feedback::
- The characters are sliding across the floor you when you move from left to right, and jump. You need to adjust the delta to fix this.
- There is no depth between the ship and the background, I personally think you could adjust the delta of the ship IMO
- The unanimated smoke is the back doesn't look so good, maybe you could animate it?
- Suggest separating the sky from the rest and giving it a delta of it's own to add more depth to the stage.
- The camera feels stiff when the characters jump, suggest a lower vertical follow & floor tension