Thanks a lot for playing and for your critical feedback! I really appreciate that you spent some time writing your comment :)
The idea behind the jump mechanics is that you have spacebar, which is controllable, but doesnt get you very far. And that you have the rocket jump, which is uncontrolable, but gets you halfway across the world. I do hear what you say though, maybe we could have given the player a bit more mid-air control.
Your second point is also fair, the camera becomes a bit restrictive deep underground. This might have needed a bit more thought.
Thanks again for your feedback! :D