Till now games was missing on Google Plus like Facebook Games but now for play games on Google Plus also. Shortly Google + rollout games on your Google Plus page. According to Google blog you will get good control on games with good experience than other social websites.
According to Google:
When you’re ready to play, the Games page is waiting—click the games button at the top of your stream. You can see the latest game updates from your circles, browse the invites you’ve received and check out games that people you know have played recently. The Games page is also where your game accomplishments will appear. So you can comfortably share your latest high score—your circles will only see the updates when they’re interested in playing games too.
Google Plus will give u option for ignore any games and continues with other. You’ll have a fun initial set of games to play with on Google+. For game developer Google Plus also launched new blog Google+ developer blog. Currently Games are not available on all Google Plus account if there is game button on your page you can start and play games but button not appearing on you Google Plus profile then you need to wait for sometime.
I just check my Google Plus profile and unfortunately game button is now available on my Google Plus account so we need to wait till Google Plus gradually roll out games in Google+. After that we can enjoy games on Google Plus also.