"Adventures" is a family-friendly, truly cooperative (yet also solo!) 'dungeon crawler' with a unique 'positive life message' mechanic - compliments and nice gestures are required to keep morale high and the party performing at their best. Playable by everyone including the very young, it's a game you can solo as a complex party-based RTS, and/or play drop-in coop with your family and friends for a more arcady, cooperative experience. It's called 'Adventures' because the adventures will be unlimited by theme. At launch it'll be a dungeon crawler, but we'll have adventures in all sorts of environments - sci-fi, medieval, fantasy, etc.
One of the earliest design goals for Adventures was flexible gameplay. I love games where you can play with the environment or situation. For example, in Champions of Norrath on the PS2, there were the occasional scattered powder-kegs. There was no mechanic to use them other then igniting them, but the physics engine meant you could crudely push them around. So I'd spend some time creating elaborate powder-keg traps, luring monsters and hopefully detonating them.
To this end, Adventures incorporates an object system that allows a great deal of flexibility. Coupled with procedural skills, there should be plenty of explorative problem solving. Here's a quick vid of an early example of 'cheating' the system to deal with spawning monsters.