I envision a short-hair-era Angelina Jolie gliding in on a hoverboard, clad in Chemical Brothers-orange cargo pants, to deliver this idea to the minds of Harmonix Studios. Their surprise announcement of A City Sleeps is a gnarly throwback to all things ’90s: Treasure-style shooters, a character named Poe, an Aeon Flux ink style, the notion of electronic music as a sci-fi savior. There’s nothing coy or winking about their evocation of the Wipeout era, which is what sells it, or, really, any other “retro” styled thing.  Due out this October, the game has you entering the dreams of a city’s inhabitants to…