This week I finally got access to Games for Google+, so I tried some of them to get a first impression. In particular I tried Angry Birds, City of Wonder, and Dragons of Atlantis. 3 games out of the 16 currently on offer.
Angry Birds on Google+ is like Angry Birds on every other platform. On Google+ your score gets compared to the scores of the people in your circles. And apparently there are multiplayer "maps". Not sure if these additions justify playing Angry Birds on Google+ instead of elsewhere.
Dragons of Atlantis appears to be one of these "build a city and attack your neighbors" games, like countless "browser strategy games" with names like Travian or Lords of Ultima. My principal problem with these games is that they do the opposite of intelligent matchmaking in a PvP game: Good matchmaking encourages players to fight other players of equal strength. By placing players randomly on a map and making it more advantageous to fight neighbors, you often end up with people having started earlier or playing more intensively completely crushing newer or more casual players without these even having a chance. Often that ends up with players hoping to make their neighbors quit, so they can have their cities "on farm", raiding them regularly for added resources. Unbalanced PvP does not a fun game make.
So in the end the game I spent the most time with ended up being City of Wonder. That is a city-building game with a Civilization theme. Curiously that ends up resembling Civilization more than the "official" social platform version of Civilization, Civ World on Facebook. On the other hand City of Wonder doesn't have much gameplay. It is just the basic Farmville principle of clicking on things in regular intervals. You'd advance fastest if you had City of Wonder running in the background while playing something else, and would ALT-TAB to it to click on some stuff every time the other game had some downtime. Compared to Farmville, City of Wonder is more complex, with a big technology tree, more different types of buildings, and more different factors like culture or happiness to optimize. But that just makes me want to play Civilization V instead, where I don't get constant advertising how I could improve my city by paying real money.
I will try some other Games for Google+, but up to now I can't say I have struck gold yet. Which isn't really surprising, as the competitor Facebook is also full of games which range from boring to just plain bad, with only a few pearls in between. If you haven't played it on Facebook, you might want to try Dragon Age Legends on Google+. That was one of the more decent games on Facebook, even if it obviously can't compare with the single-player Dragon Age games.