Hey, not bad at all for a first game! Like others have said, backgrounds and sounds would have added a lot here.
I didn't realize about the rushing at first, which was my fault for not reading. Until then I thought that the jetpack moving up was too slow, it's probably fine with the rushing and made the game feel more fun. However, it does have some bugs. With collision not working when rushing right. And there's a bug where if you start rushing, the objects on screen will scroll left faster, but new objects will move slower. So they'd be going at different speeds. Also, I think that the score should also increase faster while you are rushing.
But it's a good solid attempt for learning your first game and you should definitely stick with it if that's what you want to do!