Think about features that help attract and engage users:

• Is there a demo or free-to-play mode that allows anyone to try the game?
• Is it easy to learn so those that try don’t walk away frustrated?
• Are there clear and compelling compulsion games that make players stick around?
• Are there achievements to attract serial completionists and to incent social braggarts?
• Are there clear game mechanics to get players to invite their friends?
• Are there obvious steps to upgrade to get a higher level of gameplay?