With all of the shoot-'em-ups out there, it can be tough to find one that does something new and interesting. After a few decades of existence, the genre has pretty much seen it all. But 24 Caret Games is trying to bring something unique to shmup fans out there, with an upcoming PlayStation Network game called Retro/Grade that is played entirely in reverse.

It sounds a little bit confusing, and the best way to get an idea of how Retro/Grade plays is to watch the debut trailer (below). Players have to avoid enemy shots as they go back into their weapons, and get in front of their own shots that have been fired in the past. Yeah, watch the video.

As you can see, while it has the appearance of a shooter, things play out a lot like a rhythm game, with a strong focus on timing. This hasn't escaped the notice of 24 Caret, who has included support for guitar controllers. Plus, the game will feature an original retro-themed soundtrack.

Unfortunately, the game isn't expected to hit the PSN until sometime next year, and no price has been set yet. But if the video didn't give you a clear enough picture of how Retro/Grade plays, there is currently a PC demo available for download, which does a great job of showing how the game actually works.