Welp, I forgot how the gameplay works, so I'll do it now.
This game works like most touhou games, you collect p blocks to increase your power, dodge bullets, bomb when you're cornered, and shoot bosses and enemies.
The game's new mechanic is Tri-energy. the yellow "tri" points you collect fill up a gauge at the bottom-left of the screen. once it's full, if you press c, you can release a burst that removes all bullets within it's range and damages enemies and bosses.
Now, some of gannon's spellcards require you to bomb or release sometimes due to lack of time to polish them up, but that shouldn't be much of an issue (unless your going for a no miss no bomb).
that's pretty much it. enjoy!