The tournament definitely made for an interesting game, but more as a conversation starter than a game itself. I suspect part of the issue was how short this particular game was, but the constant cooperation got old pretty quickly. Some ideas for next time someone wants to run a dilemma tournament:

1) Bracket play - you play with another person until one of you defects while the other cooperates. Example round: both cooperate, both cooperate both defect, both defect, player 1 defects and player 2 cooperates, player 1 moves on. This has a trivial vulnerability in that always defecting always wins or ties, so there'd have to be some other incentive to encourage cooperation.

2) Factions - each person is part of a faction, you have some minor term for the total utility of your faction at the end of the game. You could go further with this and have a negative (even more minor) term for the total utility of other factions, or maybe add the option of giving points to other players.

Unrelated note: In the future there should probably be some coordination around walking to/from. While nothing happened this time, Civic Center did not feel like the safest place to be walking around alone late at night.