The game is set in a steampunk-styled 1890. The "Great Empire" is using a zeppelin to ferry raw materials from the colonies. Although security is tight, there are a number of spies and saboteurs on board. The players each take on the role of a nameless foreign power, using the agents at hand to destroy the Empire's resources.
Or, more simply put: You take turns chucking things off a zeppelin. Everything is worth a certain amount of points (Wood = 1, Diamonds = 7) - the first person to chuck 20 or 30 points-worth off the zeppelin wins. We had a lot of fun imagining the humble sheep farmer underneath the zeppelin, steadily losing his flock to falling crates of iron ore.
The game is based around a deck of 14 Traitors, each with their own special power or trait. In each turn, players get two Traitors - one randomly dealt, one secretly selected. Players go around in a circle activating one of their Traitors, then then go around again activating the second one. Each Traitor earns a bit of gold, draws some cards and (possibly) chucks stuff over the side. They do this by bribing the invisible, omnipresent guards and playing a cargo card. At the end of both rounds, the turn is over, and all the Traitors go back into the deck. Repeat until someone wins.
The mechanic gets more complicated because you can't always chuck something over the side. At the start of each turn, the first player rolls special coloured dice and the results show which groups of saboteur are allowed to chuck. Some Traitors have powers that can change the dice results, which adds to the mayhem. Also, many of the Traitors have powers that annoy and/or outright neutralize other Traitors. L'il Tim Sly, for example, can take on the persona of any other non-activated Traitor - meaning he can be a true pest. If he picks one of your agents to imitate, as you'll effectively lose a round. The sinister Doctor Ripp is more direct - he picks one other Traitor and they're knocked out for a round. Very annoying.
Strategically, we discovered that Mad Zeppelin requires the memory of an elephant and the player-reading skills of a poker expert. Knowing what Traitors your fellow players have is essential, it allows you to predict their actions and also pre-emptively defend yourself against their treachery. Controlling the dice is also vital - you want to limit the options for other players' agents while maximizing your own opportunities to launch cargo. There were times where it was easiest just to remove the dice entirely (a "black" roll takes the die off the table) - ensuring that no one can throw cargo. There's also a bit of resource management. Certain agents draw more gold, others get extra cards. Knowing when to use each agent is vital, but then, you can't be too predictable or you'll play right into the hands of the Doctor or L'il Tim.
The learning curve for Mad Zeppelin was, needless to say, extremely steep - it took us a few hours to figure out what exactly was going on. But once the mechanics become clear, the game becomes much easier - and the players can move into proper, strategic play. There were also a few barriers that added to the initial difficulty.
First, a nitpicky structural thing... The game comes with a handy (and attractive) cheat sheet of the various agents and their powers. This is very useful when it comes to both choosing your own Traitor and trying to zap someone else's with one of your powers. However, the sheet doesn't include the Traitors' "colours". So you don't know which are able to act with each roll of the die. That's very, very handy. Whether you're imitating an agent or knocking it out, whether or not they're able to chuck cargo is one of the deciding factors. We wound up writing the colours in on the cheat sheet with a permanent marker.
Second, the lack of a FAQ or any errata was frustrating. There were a few powers we didn't wholly understand - especially the more defensive characters such as Igor. The adorable hunchback (my favorite card artwork) is immune to other agents' powers. However, the way the round/turn timing mechanic went, most of the other Traitors' hostile powers actually affected Igor before he was activated - e.g. the Doctor and L'il Tim. Either we were misunderstanding the way the prioritization or timing rules worked, or Igor and a few others were fairly worthless.
Both of these are little quibbles - bizarrely, our largest problem with Mad Zeppelin was a conceptual one. We could never figure out who we were. The rules merely told us that we were taking control of various Traitors and we were trying to disrupt the Great Empire. It wasn't too hard to surmise that we were the faceless representatives of foreign powers, but the what/how/where/why of our role felt a little bizarre. The zeppelin only had a small pool of Traitors so we, as evil bureaucrats, were hiring them willy-nilly. This explains why our Traitors changed every turn, but not why we were "competing" to destory the Empire in the first place. It isn't like we were saving the cargo - the end result was still the same no matter who chucked the valuables over the side (crate of ore in a field of sheep somewhere). Eventually, we agreed that Mad Zeppelin was like some sort of slapstick political sitcom ("Carry On Airshipping!"), but that was pure rationalization on the part of the players.
However, a lot of Mad Zeppelin's flaws can be forgiven the instant you really take a look at it. The art is absolutely amazing, and even if it takes an hour to figure out what you're doing (much less why), you'll be entertained by the amazing detail on each of the characters. Every time we drew a new Traitor, we were wildly impressed - and indeed, in the absence of any understanding of the rules, the first few turns were based entirely on playing the Traitors we thought were the coolest looking.
Mad Zeppelin's playing mechanic is unique and, despite the learning curve, a lot of fun. This is an entertaining game, but one that requires a lot of focus from its players. Once we figured it out, Mad Zeppelin became the moderately-paced, extremely-conniving game that I think it was intended to be. However, a little help from the manufacturer would go a long way towards getting players to that stage more quickly.