Get your Interlock out of my Hero system!
Champions: New Millennium was basically the Hindenburg disaster for my gaming group.
In the sense that FUZION, like hydrogen was identified as the cause, and no-one was ever willing to even contemplate playing a FUZION-based RPG ever again. Also like the Hindenburg disaster it wasn't really hydrogen/FUZION's fault, it was the other parts of the airship being basically thermite, or in this case, the other parts of the airship being the very worst aspects of HERO.
It was so bad because we were so hyped. We loved Interlock. We'd play an absolute ton of Cyberpunk 2020. We wanted to play a superhero game that was a bit more crunchy than some but not at full-HERO levels. All the players spent hours coming up with great characters, really carefully calculating them out. Everyone had some kind of dreadful-but-cool-at-the-time sort of late '90s superhero. We had:
1) A guy with darkness powers who was "never going back to jail". That was the concept.
2) Some kind of flying devil guy, but like, for violent justice not evil!
3) A guy with a miniature alien fusion reactor inside him, which gave him energy blasts, super-strength, super-speed, and so on. Think like edgy '90s Superman. Of course he had extreme-sports style sunglasses, why do you ask?
4) I wanna say "Young Iron Man with attitude". This was the least memorable of the characters. All I remember is power armour and that they had a 'tude.
I had written up a "short" (as I repeatedly told them) adventure, which end with a rumble with like five villains (this seemed to be a fair fight and indeed it was). We just really wanted to see how it all worked, and expected it to take an hour or two tops. I'd done some adventures/scenarios with 1-2 players and seemed to work good.
We got to the rumble in about 20 minutes, seemed fine. I will spare you the details but well over 5 hours later, 3 minutes of combat (game time) had elapsed, and the fight was finally over.
It was universally agreed that we would never play that system again.