There are quite a number of tower defense games on Ouya, and Def is one of them. In the game Def you take the role of a human reporter talking to an alien species known as the Def. The Def want to make a peace treaty with the Humans, and have went through a rift they created from their part of space to the humans to do these discussions. You are on board one of their ships specially made for humans. Things were going fairly smooth, you getting to understand the Def and what kind of people they were, and then an unknown enemy attacks, and it is up to you and your new partner to stop them! This game is story based that allows you to make your own choices in terms of what to say to your new found alien friend. What you say will, in turn, affect relationships later in the game.