When you have a good thing, sometimes it's best to keep rolling with it. That's what Sierra probably thought with Bizarre Creations' wildly successful Xbox Live Arcade game Geometry Wars: Retro Evolved. It struck a deal to create a completely new stand-alone release out of it. Geometry Wars: Galaxies is just as good as Retro Evolved, and in many ways even better.

The concept is pretty much the same. You fly around the screen, shooting in all directions. You'll need to, as the screen quickly fills with various enemies. If the classic green baddies don't get you, the new red paper airplane-like ones will. However, where the original XBLA game only had so much to go on, Galaxies expands further in a few ways.

First off, you don't fight alone. As you journey through these Galaxies, you'll obtain helpful little drones that assist you throughout each stage. They function in different ways. One acts as a turret, occasionally mounting itself to the stage and shooting everything around it. Another "snipes" enemies by firing powerful laser blasts in spurts.

There are also various rules that affect each stage. One has power waves moving across the screen, changing gravity for both you and your opponents. Another Pac-Man-like stage forces you to work your way through grids as more and more foes fill the corridors. For each stage, you can earn either a bronze, silver or a gold medal, collecting "geoms" (little glowing spheres) as you go. Not only do the "geoms" come in handy for purchasing stages later in the game, but they also build up your multiplier at a rapid pace. You'll make 150 times the points, providing you stay alive.