If you plan release your game before Godot 4.0, maybe you can fix some of this hickups. Check this video:
I had the same issues with my game, and this helped a bit.
The art is very good.
Regarding gameplay there are some things that i did not like so much:
- I find annoying that when we take hit the plane stops in the air. I would prefer to have check points and keep the velocity in that check point
- I would make the power ups bigger. All of them.
- I would make the minimal velocity higher.
The sounds are ok, but they seems to have poor quality.
The first time the game runs, i had several screen freezes. Specially in the beggining of the level. I restarted the Game, and is it was better, but I still had some screen freezes. I run the game in Ubuntu.
But overall, it was a good experience :)
Keep the good work