So I checked him in the test chamber after an underwhelming encounter in my hard run. I'd beat him on both normal and hard in test chamber (and hard in a real game).
1) No stage 2?
His stage 1 just gets boring going on that long. Really could use a stage 2. Heck, he really should be a 3 stage boss, with stage 3 being taking out the corner stations.
2) He is probably fine on stage 1, but honestly he might be my new easiest boss now that you fixed mirror. He really needs one more minor mechanic to make it interesting.
3) Hard isn't really that much harder, compared to your other bosses.
4) I swear it might be possible to to stay in one opening and dodge the chaser using a box pattern. I can almost do it consistently for 2 shotgun sprays, so I'm not certain if it is sustainable. So if the chaser is meant to be something you just need to avoid, you might need to change its shotgun spray to something harder to evade.
Thoughts and suggestions:
For additional mechanics:
Large attacks that fill up one of the four openings. Enough to actually interrupt my rotation from one to the next each time a chaser comes out.
Secondary chaser, much slower. Maybe a long snake of bullets, almost like the pink/blue claw guys.
Hard alternatives:
Replace the existing mechanic with a rotating, wall piercing, shot going outward from the center. Reasonable spacing, but it adds an obstacle that behaves different to the situation.
Stage 2 thoughts:
Have the middle fire the bouncing orange shots instead, and have the corner stations fire an expanding imperfect ring of very slow moving stars. Combined with the existing chaser, this makes the corners a challenge to navigate through.
Stage 3 thoughts:
a) Have the stations fire a wall of shots down each of their two paths. Set it up so the player needs to duck in to the middle opens to let the shots pass, and then rush in behind for the kill.
b) Have each station fire a serpent shot that fills the entire hall.
