Retro/Grade is a game about distraction. On a surface level, there's a complicated premise that has you playing a side-scrolling shmup in reverse, avoiding enemy bullets as they return to the back of your ship and rushing to catch the projectiles that your ship fired when time was moving forward. You know, because you don't want to damage the timeline by having a missile shoot out of nowhere.

In practice, however, all that complication belies a very easy to understand rhythm game. Those missiles return to your ship to the rhythm of the song, and you move up and down the screen and catch them. It's kind of Rock Band turned sideways, right down to color coding on the markers.