DWM Apparently this has been used for aviation games, so it could probably be applied to a space flight game. (This wasn't clear from the feature list.) However, the licensing would have to be negotiated. Standard: $100/developer up front, and GarageGames has publishing rights. You get 50% of proceeds from Web sales, at least 80% of proceeds from box sales (if any). Here's the kicker: Subscription-based games require a separate, written contract with them.
Here's some more information on this topic from their FAQ on licensing:
How does the license for MMP games work? If you make money on a product, GarageGames need to make money on the product. There are many business models for MMP games, but the standard is to charge for the client, then charge a monthly access fee. In this case, the client would be purchased from the GG site, and the standard 50/50 split would apply. For the on-line monthly fees, we are willing to work with you in a stepped royalty fashion in order for you to recoup your infrastructure costs. Please email Jeff Tunnell at jefft@garagegames.com for further information.
Will GarageGames guarantee to present my game to publishers for box distribution? No. We will only present the best games that are selling well. This is entirely subjective.
Can I present my product to publishers myself? You can try. However, keep in mind that if you get a publisher interested, GarageGames must be involved in the negotiations once they start.
There's lots of other interesting stuff in the FAQ, and in the comments posted by others. The excerpt above might cause you to raise an eyebrow or two (or three, if you have that many), but really, take a look at their whole [Licensing FAQ]. I'm thinking that this sounds like a nice deal.
An equally important topic is: What is the engine capable of? Unfortunately, the actual documentation seems to only be available if you buy the engine. Some comments on the site indicate that it's not specifically designed for MMOG architectures, but you get source code, so it might be adaptable.