Okay, so, I can fling huge fireballs around with the Incineration Module. That's a thing that's happening. Sure wasn't before....
Not a complaint, mind you.
EDIT:
Okay, so, a synergy that I call The Lawnmower: That item that gives you a flame trail as you sprint, and the new sacrifice room item that makes you invincible for 10 seconds when you enter a room.
Enter a room, don't bother firing, and just kill as many things as you can simply by dashing around like a maniac. This didn't stop being entertaining.
Talk about an OP run, that one. Bought, what, 4 sacrifice items, still had 30+ max HP at the end? Very different from my run prior to that, where the Random Number Gods were very angry indeed.
Also, Boomerang Needler is still a really good energy weapon. That hasn't changed.
And did someone make a change to the "Miniature Black Hole" consumable? I seem to recall that being very... ineffective before. On this run I used it in a nasty room with like 4 fearsomes in it, and I'm relatively certain it ate the universe. 3 of those Fearsomes were dead after it faded, though I'm not entirely sure what killed them.