Thanks for playing!
Western RPGs and late-90s shooters were major influences, probably more than actual visual novels. I don't actually have a lot of familiarity with magical girl fiction.
I've been bodging together disparate music for a long time, maybe some day I'll actually have an original score. Mixing orchestral and metal music was an experiment but I think it turned out well. It started with just using tracks I had around or grabbed from the front page of OpenGameArt and vaguely fit the scene but I decided to run with it.
I had some of my friends test near the end and they were very confused about what to do in that level as well. I added some extra dialogue at the last minute in an effort to fix this, but it was very much a half-baked, rushed thing. Basically, you need to reach the door on the upper storey of the keep. You can do this by power jumping either from the roof of the church or the buildings on the other side.