The box comes with two rulebooks. The first contains the actual rules, and some stats for the models, along with a pretty good quick reference sheet on the back
The second book contains all the narrative for the events that can occur during the game. Some of these are triggered by certain rooms stating "read passenger X", whereas others are random effects gained at the start of the turn from a 2d6.
Each character has a unique "stat card". The action system is very similar to that of Plaid Hat Game's Dead of Winter. At the start of the round, you roll a D6 for each remaining wound you have, and based on the results of the die, you can take certain actions. Usually a basic attack, in addition to move and exploring require a 1+ (so any die result can be used, but it still uses up that die), whereas more elaborate attacks and skills will require a certain result. The warrior below can use the Broadsword swing on a 4+, and the Charge skill on a 6.
All in all, the game plays very quick, and it's fully cooperative with the dungeon playing itself.
The quality of the board game tiles is really top notch, which I did not expect. I'd say they are nicer than any Fantasy Flight board game tiles I know of.
The game is simple enough that wives, coworkers, and other non-gamers can get involved, and since it's coop, you can help them along as well. It makes a great "beer and pretzels" casual game night event!
If you're a fan of dungeon crawlers and can stomach the US $150 price tag, I highly recommend giving this game a shot. The figures are worth it alone if you want to paint them up, and GW continues to make the best quality figures on the market. Many GW stores and local game shops are still running demos of the game as well, if you'd like to try it before you buy it.