Not buggy...
I hardly think having the catapult keep firing after you finish a level is a bug, it's kinda fun that you can keep firing and it doesn't count towards your throws for the level. If you clicked restart by accident then you must have been clicking rapidly which isn't the point of the game.
I don't think bending celery sounds much like a catapult tbh. And a collision sound would get really annoying quick (it actually does have a collision sound but it's quiet so it doesn't get annoying)
Etc.