Hi! We've created an action-puzzler for iPhone/iPad and it was suggested that Game Center implementation would be a nice addition to it. Now, first let me emphasize it was never our intention to add cherries, stars or chihuahuas and make our players collect all of them. We'd like to come up with something more sophisticated that would fit the gameplay. And of course, we know this highly depends on the game and it's even difficult doing this after the game has been designed. We'd only like to ask you if you have examples of achievements or leaderboard-challenges you really like and think are a great addition to certain (action/arcade) games? We're after the kind of achievements that are generally appreciated. And if you do like collecting cherries, stars or chihuahuas, please let us know as well, maybe we can fix something. Thanks for your time!