Trading is going to be a huge part of the online aspect of Cities XL. Depending on where you choose to build your city, you'll have access to some resources, but not others. If you're looking to become an oil baron, chances are you're not going to have much fertile land around you for agricultural pursuits. So you'll need to trade some of your oil tokens for agricultural/food tokens. The entire trading system is centered around these tokens. Your city has a long list of requirements, all of which work on sliding scales. If we take the above example, your oil requirement scale would at the positive end of the scale, earning you an excess of oil tokens you can use to trade, while the agricultural/food scale would be in the negative, affecting the happiness and productivity of your citizens. The system is actually very well thought out in regards to keeping the game balanced and fending off 3rd party farmers/traders. Everything operates on a barter system, there is no other form of 'currency' beyond the tokens representing the various resources. And you can't stockpile tokens, they vanish/reset every 24 hours. So, again, using the above example, if you have a +5 on your oil scale, that gives you 5 tokens of oil to trade each day, but if you don't have contracts in place to trade them to other players, they are "taken" by the NPC government in the game at the end of the day. This is a safety net type of system which will prevent cities from coming to a screeching halt and dying if the player can't find someone to trade with for the resources they need. If your city is in the negative for agriculture/food, you will get what you "need" from the NPC government mentioned above, just at a much greater impact to your citizens productivity/happiness than if you got it by trading with another player.
Trading is also limited/affected by your transportation infrastructure. Each plot of land has a different number of "city links" connecting it to the rest of the world. Connecting your city to the city links on the borders of your map connects you to the rest of the world, and naturally the more connection you have (number of major highways or waterways, etc, connecting 2 or more city links) the more transportation slots you have, which allow you to trade more with the other players on your planet/server. This is another facet that could greatly be affected by future GEM packs. Say down the road they release an Airport GEM which allows you to build a massive international airport. Naturally you'd have to use a large section of your map for its construction, but having it would greatly increase your connectivity and give you an immense number of transportation/trading slots. Which you could then use to turn yourself into a trading type setup, not manufacturing anything yourself, just bringing in large amounts of tokens and trading them back out to others.
All that's well and good, but if the game doesn't play well, it doesn't matter how many great online features it has right? Well, to give you an idea of how well it plays, when I was in the Monte Cristo office, I spent the morning part of the day talking about the game and watching a demonstration. Then after we went to lunch, I got my own hands-on time with it. It was about 13:30, maybe 14:00, when I started playing and I swear, next thing I know, Philippe had come back in the room and told me it was 18:30 and we needed to get going... I was completely shocked that much time had passed, I was so engrossed in the game it only seemed like maybe an hour had passed, tops. The mechanics of the game will be instantly familiar to anyone who has played a city builder before. They've taken both of the 'usual' play styles into account, you can use either the 'zone' or 'plop', or a combination of the 2, to construct your metropolis. And when using the zone method, you're not limited to just squares and rectangles, you can use custom shapes as well. Many things are also really dynamic, take for example if you're building a road; if you "sink" the road as you're laying it out, it will automatically become a tunnel, same with if you raise it, bridge. The map is completely grid free, giving you absolute freedom in where you can place your city. Naturally, the terrain you select will affect those choices some, for example if you have a mountain range or canyon running through your map. Which brings up another great point: Difficulty won't be determined by the amount of starting money you receive, but rather how difficult the terrain in your given map will be to work around. All of the normal statistics and information you'd expect to find in a city builder are readily at your fingertips, making controlling your expanding metropolis a breeze. The game is also very good about notifying you about problems that crop up, unemployment rate too high, too few executive level houses available, etc. And with a simple scroll of the mousewheel you can go all the way from a satellite view of your map to walking around the city as your avatar in a very smooth and fluid transition.
All in all, Cities XL is a very ambitious project. It's never an easy feat to bring a new type of game into an existing genre. Unfortunately the current "common" mindset is that if something is an MMO, it must usually contain orcs and elves, swords and magic, or even the occasional spaceship and lasers. This is definitely a mindset that we need to move away from in order for the MMO genre to grow. There is a lot more room in the genre for things that don't end in RPG. Cities XL, in my opinion, is definitely on the right track to bring something new to the genre, and do it very well in the process. I was already eagerly anticipating the game, and after getting my hands on it, I can honestly say it has only increased my anticipation of the title. Monte Cristo is currently accepting applications for the closed beta, so head over to this site to register. And don't forget to put in MMORPG.com's exclusive code MMO123 to increase your odds!