In our group's first game together, I was able to draft 2 Camaraderies and remove some cards from my deck - every floor, every turn, it was an infinite - Camaraderie draws Camaraderie. One of my friends got Fractal Whip, which easily gets reduced to 0 mana, and we proceeded to steamroll (almost) every encounter after - including the final boss. My other friend got Garbage Day and got thousands of block turn 1 every game from that point on too. Getting a Toy Compass which then gave me infinite mana wasn't even required, but made it even more silly. Only Skull Spook was even close to scary - but as soon as we got past him, everything else was an OTK.
We haven't unlocked Torment difficulties yet, which will presumably prevent this through some mechanism (like Across the Obelisk's +1 mana cost to each drawn card if you cycle your deck). It really ruins any fun (on the lower difficulties), because at least to our group, this is such a dominant and easy to achieve strategy that it drowns out everything else.
Recording of OTK'ing the final boss: https://streamable.com/gg9t31