Let me say that, at this point, we have enough enemy graphics to where we could have one unique type for each sequence. If something happens to rrrrreeeeeaaaaallllyyyyy slow us down, we won't have to worry about having the necessary animations.
The only things we're missing now that are somewhat crucial are the Game screens. If you have ideas for those, let me know.
I'm making the Boss Fight background be a balcony on the tower. A small part of the screen will be reserved for flying space, with the assumption that the boss or some of his spawns will be flying. A night sky spans the whole screen behind the tower/balcony.