'Planet Offer' is the online mode where players can trade and visit one another's urban creations, and will cost EUR 7 a month or less if you opt for more months at a time.
If you decide three months subscription then you end up only paying EUR 5, or even 50 cents less for a full 6 month sign on. Singleplayer will be populated with AI cities to trade with but it's unlikely you'll receive all future game updates for free.
Planet Offer comes with five slots per player to build five persistent cities, one for each 'planet' says Monte Cristo. "From day one we wanted to make sure that we were going to compete with the most ambitious builders out there in term of content and functionality," said Patrick Marchal.
"We wanted the players to first enjoy Cities XL in solo mode, and then convince them to join the Planet Offer, which will open the gates to a more ambitious level of game experience."
The tragedy is it takes a non-SimCity game to fill the void in the wake of SimCity Societies, which left many fans hurting for a full number 5. The French developer has cleverly been paying attention to the SimCity base community and incorporated a number of their desires.
Cities XL is shaping up nicely and letting would-be Mayors show off their creations online, not to mention letting them trade and collaborate, should deliver one heck of a game for builder fans. The game is due for release this year on PC.