gravity_affects_ships ... of course. Thanks. It is possible that I was having too many overlaping gravity effects and that was affecting things. It would be nice to have a nonlinear gravity function, but this works.
effects ... these guys give me a bit of a headache honestly. Using them to add and remove systems from other entities to create timing events... Or using it to add a weapon system to another entity (or to take that weapon away).
Thank you, Misery, Keith, and Cinth (reverse alphabetic order, no favoritism implied)
Mechanics have been added to the Invader Boss, I'm not good enough to test Misery mode balance.
New miniboss/boss is about half done. I really like him/her/it. I was trying to make a miniboss, but my playtester informed me I was making a boss.
Control over image rotation of a shot rotating around a pivot point is proving awkward. I finally got shot_is_not_stopped_by_hitting="true" to make the shots no collide, I'm not sure what the other tags like Self_NotDestroyedOnCollisionWithShip do then.