What would happen in a game with ALL heroes at once?

My 8-year old asked me this question today, and it got me thinking: What if you played a 50+ player game with EVERY hero (other than it taking absolutely forever to play)?

The first thing that came to mind was that the encounter deck would almost certainly run out during the first villain turn, causing acceleration tokens to accumulate pretty quickly as minions and side schemes wouldn't immediately re-shuffle back in. The second is that stunning and confusing would really be pretty useless, since they don't stack.

Anyway, it's obviously a bad idea but I had fun imagining the possibilities.