We had 13 teams, of which 4 completed all of the puzzles. The most submissions for a single puzzle was about 95. 713 submissions were made. 141 puzzles were started, 111 puzzles were answered correctly (this includes some of our test accounts, however).
Things I think I should change for next time:
1) Promotion! We really didn't have much time, but we could have planned it better and advertised a lot more, probably. Cooperation with ACM to get things into the ACM R|P conference booklet would probably have been really good.
2) Registration: Should change to FB Connect / single user registration, then add yourself to a team.
3) Hints system: While the scheduled hint release system was really nice (and kept team->Game Control communication to a minimum), maybe hints should have been released x hours after each team started the puzzle. Means an extra DB hit each time a team hits a page, but that should be ok.
4) Prizes: ACM got prizes for us, but it was kinda last minute, so we could only buy gift cards. :\
It's pretty amazing to have done this though. Feedback-wise, the teams that tried it really enjoyed my puzzles (especially the nyancat regular expression) and the origami puzzle worked, which was awesome.