This is really promising so far. I love the spritework and the music and you captured the classic megaten vibe super well. However I can't say I'm a fan of the hijacking system as it functions currently. The idea of using danmaku instead of negotiating is really cute, but the 50sp cost to even attempt it feels like a really unnecessary limitation considering how easily you can fail it even after that, and because of that I kinda found myself unable to actually get any more party members other than Satori for the longest time since by the time I actually was able to build up to trying I would fail it. I'd say either remove or lower the SP cost for attempting a hijack or make the actual hijacking process a little more lenient rather than 2 hits being a fail and locking you out for the rest of the battle. Plus I feel the encounter rate is a bit too low which doesn't really help the above issue either. Still, great work so far and I'm interested in seeing where it goes from here.
Edit: I later realised that you don't get locked out of trying a hijack again for the rest of the battle, just for the turn you tried it, and also that the encounter rate is significantly higher in the hell area. However I still stand by my other points.