It's an okay addition to the already awesome Arkham City, but it could've been left out altogether.
Robin plays almost similar to Batman with a few additions and removals from his arsenal. They both have projectiles to interact with the environment or knock thugs down. While Robin can't disarm thugs like Batman can, he can plant a stun bomb on anyone who don't suspect him, use his bo as a weapon in hand-to-hand combat and turn it into a shield to protect himself from gun fire. Along the way you piece together what happened to everyone's favorite caped crusader and just how messed up Harley Quinn is after the end of Arkham City.
In all honesty, this DLC either should not have been added or would've been better off as an added content on the game itself as it would take just about an hour or two, depending on how fast you play, to finish this mode. Even though they have collectibles to gain, they're not worth it. Nor is this actually worth it for the price that they were giving out at the time. Only if you really like Batman, would you consider purchasing this.