Like Mark, I really enjoy it. It's got a great teamplay dynamic, and works quite hard to prevent an expierenced or powerful player from dominating newer or less powerful ones. The Crossfire deck mechanism is a really good way to escalate tension as well. I'm really looking forward to the first full expansion for the game,
I'd make a couple of recommendations: Download the additional missions from the game's website. Ambulators is a slightly easier version of the basic Crossifre scenario (you face two waves of enemies instead of three), close the portal is a fun mission that's not too difficult (we beat it twice on Wednesday with four runners, each of whom had one upgrade), and Enter the Ork Underground is a more difficult one that we're not powerful enough to play yet.
Also, get the character pack. You only get 10 character sheets in the basic game - 2 each of human, elf, ork, troll and dwarf, so if you have more players, want to have more than 2 of any race on your team or want to try different ones out, this pack has like 5 of each (all with different art), and a second set of upgrade stickers, and 4 new versions of the basic damage card with different art, which is nice to have. There's an upgrade pack on the way with pre-generated prime runners as well.