The recent update removing gunpuppy blindspots makes the arena's third room impossible and unable to complete.
Anyone who's done an area since will agree.
Either:
1. Put the blindspot back
2. Put the blindspot back but only for t1 and t2
3. Put more treasure boxes and minerals at the end of arena.
It's still *possible*. It's just really damn difficult. But I agree: if I was looking for a Bullet Hell game I would go play Ikaruga. Seriously, 12 gun puppies is too many to have them all shooting at once, especially in T3. With the blindspot, though, that scenario is manageable.