The black hole suns are from... Spacewar!
You thought I was going to say Soundgarden, didn't you? But no, in what's either a deliberate nod to the granddaddy of gaming or just an incredible co-incidence (we'd guess the former), the black holes or 'gravity wells' in Geometry Wars 2 feature a gravitational system that's virtually identical to that of the central star in the 1961 computer game.
Above: Geometry Wars' gravity well (bottom-right) is almost 50 years old
The control system is from... Robotron 2084
There may be countless twin-stick shooters around these days, but Eugene Jarvis' 1982 classic was the first to use a twin-stick system for independent movement and shooting.
Above: One stick to move, one stick to fire. It'll never catch on
The splitting enemies are from... Asteroids
The asteroids in Asteroids may not fight back, but they do break into smaller enemies when you shoot them, which means shooting them makes them even more dangerous. While we're on the subject, Super Stardust HD basically IS Asteroids HD, what with its... well, asteroids.
Above: Geometry Wars 2 invades Asteroids' space thanks to Photoshop
So why is Geometry Wars 2 such a big deal?
Because it embraces its retro heritage and delivers a brilliantly constant, action-intense playground for a variety of gameplay variations. Machines from the 1980s on which the game is clearly based could never have replicated the number of on-screen enemies and special effects here, making this an incredible modernisation of retro values. The inclusion of Xbox Live online scoreboards turn arcade cabinets' high score tables into a worldwide hall of fame.