I feel like I liked this more than I should. I mean the plot is pretty bare bones and kind of dumb, but there's something weirdly charming about the package as a whole. The world is distinctive and well designed, and after watching n a whole bunch of 80s OVAs lately, it's really nice to see mechs that aren't just designed to look like they came out of Gundam or Macross. That said, what really elevates this into something decent is the direction. Yuyama kept this whole thing surprisingly atmospheric, and he gave us some pretty good action setpieces. Seriously, these things were good enough to make me like an anime where a girl gets bikini armor and super powers after falling into a flower for no adequately explained reason.
I don't know if I'd quite call this a hidden gem or anything, but I had a good time.