Excellent Game, But Get Colonies Instead
What impressed me most about this game was the multiplayer. Its focus on Japanese fighting game style tech rolls and i-frames really makes it different from every other shooter on the market, as does the emphasis on platforming and grappling in very vertical levels. The single player is a blast for one or two run-throughs, but the multiplayer has kept me coming back for a year and a half now. It has a sizeable community, too, although most if not all have moved on to Colonies.
If you're considering buying it, make sure you get the Colonies edition instead. It contains several new additions to the single & multiplayer that greatly enhance the game, and is the same price as this version new (only $30 USD). Highly recommended.