Yes, it's the obligatory "404" joke. Minineko pretty much explains the entire comic.
Mars: http://i.somethingawful.com/inserts/articlepics/photoshop/09-08-06-games/Apocalypse-Dude.jpg i dare elroy to explain this Mars: on account of 1. it's guitar hero Mars: 2. the guy is, apparently, scorpy