User blog comment:Damac1214/Mob of the Dead Achievements Leaked/@comment-173.2.116.251-20130413125457

The Easter Egg achievmet is gonna be Pop Goes the Weasle, and my guess is that at one point in MotD you can/have to restart the game to round 1 (via Afterlife probably, maybe a time loop like Shangri-La) and that that is a cycle. Also when the Blundergat in the BTS video fired those acid-dart things, it probably wasn't PaP'd, it was upgraded from the kit.

Also GG Bridge can stand for Golden Gate Bridge or also "Good Game, Bridge."