You can now unlock this achievement by rating 25 different games in the app.
To do this open the app and click on the 'My Games and Apps' tab. Now enter into each game pressing
and press the 'Rate game' button on the left below your gamerpic and choose one of the 5 star options and press
to confirm the rating.
Do this 25 times for the achievement
Note you can only rate game's you have played.