So this is a little something I've been playing quite a bit recently, and I thought would be of interest to you guys.

Starward Rogue is in many ways a lot like your usual randomized twin-stick dungeon crawler, so what's the different about it?
Well some of the room are like this:
http://i.imgur.com/kuqVHQA.gifvAlso the bosses are like this:
http://i.imgur.com/JjFGt6k.gifvActually I guess while I'm at it here's the rest of some random clips of me playing Hard mode (and dying occasionally):
https://www.youtube.com/watch?v=yIJzTjzQPkoOk, so you probably get the idea by now.
This thing is kind of like a Binding of Isaac but with more bullet hell, and not just the "shoot a lot of slow projectiles and call it bullet hell" kind either, but with effort put into pattern design.
Depending on who you are, that might be exactly what you're looking for.

The game also has "Easy", "Normal", and "Hard" difficulty modes, and yes bosses and enemies do change bullet patterns with varying difficulties in addition to the usual buffs.
If you can 1cc Touhou titles games consistently I recommend starting out on Hard right off the bat.
The game still has an additional "Misery" difficulty still being worked on which will be added in the near future (the current "Misery" difficulty is a placeholder at the time of this post).
The game is also very moddable, and allows for the addition of new enemies, bosses, bullet patterns, and rooms with relatively little code. See the game's forum on the developer's site for details.
Steam link:
http://store.steampowered.com/app/410820/Oh yeah, the story...
Well the protagonist is a multi-headed space dragon and they're trying to rescue some mysterious robot guy from this complex built into the side of a star.
To do this you they cut off one of their own heads and put it into a mech, which then gets sent into the the complex to fight through the floors, and they can keep trying because their heads grow back.
A rather funny in-universe justification for having multiple tries at dungeon crawling I guess. :V