A stage in Siphon Spirit is broken up mainly by casting reveal spells. When you cast a reveal spell more gameplay elements are introduced and some might even be removed. Through a series of reveal spell casting you can craft a level with a lot of different things going on.
But sometimes, that's not enough. Say you're building a frantic level where you need to dodge blasts and you just can't afford to lose any energy. If the reveal spell is around then you need to not only dodge the blasts from the demon hearts, you also need to make sure you never get close enough to put energy into the reveal spell or else you'll be too small to finish off the hearts.
In order to handle things like that, we've added triggers. Each part of a level can have a trigger to tell it when to get activated. We can tell it to happen a certain amount of time after the reveal is cast, to happen when there are only a certain number of a certain type of orb left (like 0 hearts on the screen), or even how much energy a certain orb has. This can be really helpful for stuff like giving some extra free energy when the player's orb gets too small.
I think I'm about halfway through with getting the editor all working now. There's another Indie Game Night coming up on the 30th, so I'm really going to have to push it in order to get it working in time. Wish me luck!