The famous crazy game where you throw potatoes away to find more potatoes to throw away to find more potatoes to throw away !
Ok so the Gunner is said a boss because it has homing defenses similar to the rockets of the potato hunter. You will find him on a small planet East of the Alien planet and near the astropotato.
As for the meteor it may be a bug, others had the same thing. I could do a bug fix to patch it, but doing so will need to restart the saves of the ones that had the bug
But in some cases the bug resolved randomly after some time. It may be due to the random positionning of the meteors and the fact that one got out of the scene and disappeared without counting