The trackball is a piece of arcade hardware that is evocative of its time, and in particular a quartet of legendary games from Atari: Missile Command, Centipede, Millipede and Crystal Castles. James has so much fondness for these games, that Krissi indulged him by letting him devote an entire episode to them. Okay, she didn't need much convincing, as you'll no doubt hear when you join us on this monumental 25th episode of GSI! An occasion so minor we forgot to mention it ourselves. Oops.