And a few more spoilers, which include the ending.
I finally finished the game. Turns out killing the bad guy didn’t actually kill him, so he came back. His plan was to ignite all these crystals and blow up the pit and all its inhabitants. For completely good reasons too, he wanted to sacrifice them all to create a better blood seal to keep the big bad god thing from escaping its prison.
I had a choice to either leave the pit and save myself or follow after the bad guy and stop him from killing everybody. I chose to follow after the bad guy, and I got a pretty great ending. It was super sweet.
I highly recommend playing this game. Of course if tower defenses aren’t your thing, then this probably isn’t for you