Rooms seem way harder, Apollyon, AB+, or RNG?

So far, I had this nightmare of a room on floor two http://images.akamai.steamusercontent.com/ugc/96098704690670489/B0FD57B81C3B1E65C9126A1F5DE21210133A73C1/ and I wouldn't be surprised if those portals are connected to playing Apollyon.

But then promptly on the next floor I ended up in a normal size (non large) room with ~20 of the white fatty enemies, 70% of all ground in the room was filled with enemies. Never seen NEARLY as many as that in a single room, and they instantly smashed my face in with nowhere enough damage to kill them and nowhere to run (parts of floor were missing too, but not enough to mess with their pathing).

I'm not necessarily against it, difficulty is fun, but my first run alone has had worse rooms than the entire journey to 1001% ever did.