There are games like Dominant Species or Conquest of Nerath that require a dedicated group of people getting together for the expressed reason of playing that particular game. The rules are a bit dense, and you need to concentrate on what you’re doing. Then there are the middle of the road games like 7 Wonders and Small World Underground where the rules are definitely there and you kinda need to concentrate but there’s more of a social “hang-out” thing going on.
Then there’s the 3rd group of games, where there’s only a few simple rules and are better played while socializing. Zombie Dice (and to a much much lesser extent Cthulhu Dice) is the epitome of this game. You take your turn, pass the cup to the next person and go back to socializing and ignoring the game in general until it comes back around to you. We’ve done this with large groups at the bar and at PAX and it’s perfect. Ice Dice isn’t quite as simple as Zombie Dice, but I’d still put it in the same category and will definitely be packing it the next time we’re at PAX or another con.