ok. as this is your first game it is quite good actually. your physics are okay, i like the music you chose.
things you might improve:
- i spend way too much time to figure out how to get in the game itself (it is 'enter' for those who may be struggling with that)
- you should add a menu. it makes things way easier.
- make the free space bigger so you can jump better and more realistic, not only in the width but in the height. only some kind of bug in the physics that allowed me to kinda hover saved me a lot of times
- maybe add some enemies. make greater levels, make it harder for me to reach the goal
continue that path guys