Geometry Wars: Retro Evolved and later Geometry Wars 2 were some of my favorites one the Xbox 360. Dual-stick shooters with awesome, simple, crisp graphics that, during the transition from CRT to LCD TVs, made LCDs look GORGEOUS.

3 is a phenomenal addition to the series (if relatively old now). It has all the modes from the previous two, and an “adventure” mode. Fantastic pick-up-and-put-down title to play when you have a bit of time or need something to distract the ADHD brain. And it’s cheap!