Thank you so much! Don't worry, I'm still bumping into walls while playtesting :D Well... but I think that's the main part that's fun. If navigation were that easy, there would be no real challenge anymore :D
I know there are some frustrating collisions with the walls, where just a few pixels stick out. I made it this way so that the sonar looks a little bit rougher instead of like a straight line. Maybe I will create a separate collision for the player and the sonar on the walls...