Fantastic art! I kept admiring the planets, each and everyone is so nice and fluid. Is that a shader material that you have applied? Could you share a tutorial perhaps?
The music is calming as well, it helps...
...because gameplay wise, it is a bit too difficult. I saw your comment that this was done deliberately but I believe it takes away from your game. The only movement I found to be somewhat helpful reaching the flag planets, is a slow a crawl as possible, with small presses of all three WDA buttons to stabilize the aircraft, hoping it will move towards the general right direction, with enough fuel (because to get the ship refuelling it needs to dock with its backside... that is even harder to pull of
And it is a shame! Because your destructible spaceship not only looks and makes awesome sounds, is programmed to break depending on the place it gets hit, but fits very beautifully with the world you have crafted - except the gravity :D. As @Crowded Games mentioned, it seems a bit off with your environment design.
Please do not get me wrong! You have done an amazing job on so many levels, like I can't do half of the stuff you pulled off! The menu transitions? The level selection? Only your third game jam? Amazing!
That is why I spent this time typing :D
I am too excited! Hope it doesn't come out the wrong way, but your players won't be able to appriciate all the hard work you've put in! (I personally suck on that big time, and your game has made me reflect a lot, thank you :D).
Personally I only managed to reach Level 2 after 10 minutes (did you also change the controls a bit from Lvl1 to Lvl2?)
tl;dr: a bit too hard, in such an awesome game! If you want extra difficulty, make it an option perhaps? I am not too good at programming and Godot, but I suppose an "if" statement somewhere could make this allot more accessible to many people. Keep up the good work, and again, hope I have not offended.