I think there should be more multiplayer online games for co-op style so that its not single player boringness. co-op adventures and so forth. just an idea
Skyrim has been rated Best Game of the Year by multiple organizations, and it's singleplayer. I do see where you're coming from though. But the problem is, multiplayer games take servers, and servers need to be paid for, which means the game stops being free, which means you have to pay for it. Thus, we find only the best games get to be multiplayer for free.
Go check out the "MMO" category on the site. These should all be multiplayer to some extent, and we are adding new ones often now. Something that suits your style should be coming up soon...
