I think this is a fun concept. Good work in a game jam timeframe. If you want to take it further afterwards then it would be fun to focus on more on that concept. So as somebody already mentioned - maybe you can jump up through clouds but they stop you from falling down. That'll make it feel like clouds are more fluffy and not like ground. If you had time you could also add indicators of height. So maybe you can see a bit of a mountain in the background to start with. Then higher up the occassional bird flies past, higher still an airplane, and higher still a space rocket. So many possibilities. Good job.