Is this as good as it gets?
The editor seems kind of hard to use. For instance it's hard to figure out where the player ship will start; there seems to be nothing marked on the editor map for this. It definitely isn't at the place where you put a 'player ship' sprite. That just sits there, while the player starts somewhere else. It's a pain that you can only drag to enlarge and tile a sprite from one of its four corners. This makes adjusting tedious.
I am also having a hard time making my walls stay visible. Some factor I don't understand makes them flicker on and off when I try to play my custom level.
There are only scripts for exactly the bosses of the game, so you can't seem to make even a normal enemy, such as a pursuit Guardian, count as a boss. There does not seem to be a script for a teleporter, so I can't make the 'endless corridor' that I was planning. It seem harder than I was hoping to do anything very original.