Can't say I know of another first-person bullet hell. Although very challenging to get there, I was able to encounter the green ball boss and pop it after a few tries. But the random spawning of basic enemies makes it possible for them to spawn right on top of, or behind, the player and dish out one, two, or on one particularly upsetting instance three consecutive hits without alerting the player to the problem.
Keep moving, no matter what, and lead your targets a little. And don't try to counter a charging enemy by shooting their projectiles, their RoF is much higher than yours.