I believe this mission is centered around the process of game development and the post-creation player testing. We learned about the different way that the players and Intended audience help improve a game. Its a win-win for both sides; the play testers get to play a new game and the game developers get to learn about some things they could improve on in their game! They also can look at their target audience and figure out whether or not the game their creating is meant for that audience.
Summary
Junior Programmer mission 3
Unity Learn