I actually played the free-to-play Bullet Run at E3. Oh, how naive I was back then. If you read the article, you'll see that I actually sorta enjoyed playing the game on the show floor.
When it was released, I finally gave it another whirl, with some pretty fond memories of that E3 experience. The real game, however, was pretty awful. The grind for in-game currency was one of the worst I've ever experienced and the base game was incredibly shallow. The audience was also incredibly small, which is probably the biggest factor convincing SOE to shut it down.
Bullet Run will make its last gesture on March 8, 2013.
Um, That Was Quick: SOE's Bullet Run Done In March [Rock, Paper, Shotgun]
Here is SOE's official statement, from its blog:
"After much review and consideration, Acony Games and Sony Online Entertainment (SOE) have mutually made the decision to discontinue development on the free-to-play FPS game, Bullet Run. As a result, SOE and Acony will sunset the game and end all game services for Bullet Run on March 8, 2013. We would like to thank the players for their dedication and support of the game."