I am in the process of creating a Batman-based pong game using the program Scratch. Approximately 80% of the game has been coded and works, so I had my roommate test it out.
The first thing I learned is that I need to create a screen that displays the directions of the game. In the future, potential gamers who are looking for my game might search for "Batman" and "pong" to find my specific game. People such as that most likely don't need instructions if they are familiar with the basic concepts of pong, but it's another story for people who don't play games on a regular basis, or at least have never played pong before. (I realize I may have heard a few shocked gasps at my last sentence, but there really are people who have never played pong...my roommate being one of those unfortunates.)
Sadly, my roommate played the game a few times through but experienced glitches in the game. Most of these revolved around the Bat-signal (ball) sticking to the manhole cover (paddle) rather than bouncing off of it. Also, the game will progress players to the next level of the game, but only for about 5 seconds before showing the Game Over screen. And when the Game Over screen is displayed, the game doesn't "stop all" like I have it coded. Once these glitches are resolved I believe that my usability testing will be more informative. But even as it is, I did learn that I need to provide some sort of instruction for players at the beginning of the game.