There is a point where - depending on the gamer - Vanquish clicks or falls apart. For the first gamer, it becomes a beautifully chaotic waltz of rocket-sliding around a crumbling space colony and shooting robots in the face. For the second gamer, it becomes an intolerable, controller-snapping exercise in frustration, cheap deaths, and unintuitive controls. For a hypothetical third gamer? Let's just say that it's somewhere in between.
Before that tipping point, Vanquish feels like an oddity that doesn't quite know what it wants to be. On the surface, it has all the trappings of your typical Western-made shooter: big, burly, super-macho American space marines with voices like they took breakfast in a gravel quarry, comically evil Russians, and combat that heavily revolves around ducking behind chest-high walls to shoot people who aren't hiding behind chest-high walls as well as you are. Beyond that, though, it has the soul of one of those hyper-kinetic Japanese action games like Devil May Cry or Viewtiful Joe - both, not coincidentally, games that sprung in part from the mind of Vanquish boss Shinji Mikami.
As DARPA agent Sam Gideon, you have a mission to accomplish: A rogue Russian faction has come into power, taking control of an American space colony and using the colony-mounted energy beam to annihilate San Francisco. You and the hypermasculine space marines who will be providing cannon fodder for the mission need to storm the space colony and take it back before they do the same to New York City. If you can rescue the genius professor who designed the thing, so much the better.
Thankfully, said genius professor also designed you a suit of power armor. The Automated Reaction Suit - or ARS - is your armor, your tool, and your weapon when fighting those dastardly Reds. Some of the high-tech gadgetry in the ARS is just a sci-fi justification for standard gameplay mechanics: Your BLADE system can replicate any weapon it finds at a nanotechnology level, but it can only store three of them, which is essentially a fancy way of saying that you can only carry three different guns at once.
Sam can't jump except at predetermined parts of a level, but with the ARS, he can certainly slide. Jet boosters in the suit let the player quickly skim along the ground in any direction, whether to mount an assault or to get out of a sticky situation. It makes for fast-paced, highly maneuverable combat in open areas, which is a welcome change from the standard cover-based mechanics we're used to.
However, the ARS' boosters share a resource - heat dissipation - with the other primary gameplay mechanic, a hyper-focus "bullet time" slowdown that highlights enemy vulnerabilities to Sam and lets him carefully aim and blast away. If the heat gauge runs out while the player is using either one, Sam enters an "Overheated" state that leaves him vulnerable, unable to use any of his fancy tips and tricks - or even to do something so simple as punch the bad guys.
Ordinarily this isn't a problem. In fact, it's actually pretty fun to rush through a battle, alternating between sliding from cover to cover and blasting your enemies in slow-motion while keeping a careful eye on your heat bar to make sure you're still within acceptable limits. There's just a single irritating spanner in the works: When Sam's health is critical, the ARS will engage the bullet-time automatically. In theory, it's a great emergency option that lets you pick off whoever's shooting at you or get into cover, giving the player a "get out of jail free" card without diminishing their skill.