The patterns aren't hard in any way, at least to me as an arcade player, the game is just clunky, I felt like I was fighting the engine, the graphics are good but the dashes feel horrible, also, I think I feel inertia, bullet hells should not have inertia.
This may feel like an harsh review but I'm not trying to appear as an harsh person.
If you have a day where you're gaming and ran out of podcasts, I really recommend this one about shmup design in general: https://www.youtube.com/watch?v=ij5trBPbJPw
This game is in no way a shmup but judging by the bullet hell maybe you would be interested in watching this.