Despite the bombast and flair, Vanquish is actually a rather run-of-the-mill shooter that manages to devolve its genre, rather than evolve it. For instance, Sam's rocket gliding ability is governed by an energy meter. His melee attacks are governed by the same meter. Yes, you read that right, Sam actually needs energy to punch his opponents, and once he's landed a successful punch, he can't glide away since the energy meter completely drains. Several times, I punched an enemy, failed to kill it thanks to Sam's lack inability aim his punches properly, and was killed because I could neither defend myself or swiftly escape.
So what does this mean for the overall game? It means that, when you get down to it, Vanquish is just another cover shooter with shallow gimmicks that have no applicable use. Sam's glide ability is only useful for escaping (or trying to), since there's no point getting up close and killed because you have no power left. Any thoughts you had of sliding toward an enemy, murdering him in a flurry of punches, and deftly sliding away like an awesome space ninja better be abolished from your head -- everything you do in this game makes you vulnerable, weak, and ultimately dead.