Thankfully, Mercenary doesn't rely too heavily on gimmicks like most Vita-exclusive games do. The touch screen is used, but quite sparingly. When meleeing enemies, you'll have to swipe the screen based on an arrow that appears. I actually quite like this addition, as it no longer guarantees a kill when you're near other enemies. If you're too slow (or swipe incorrectly), you're left vulnerable. Some of the gadgets from your "Van-Guard" may also take advantage of the hardware--but these don't seem to distract from the core gameplay. These tools, which recharge as you kill more enemies, are reminiscent of the remote drones you control in Black Ops 2. One particular one I used let me fly around, lock onto enemies, and claw at their skulls (ouch!).
One concern I have about Mercenary is that each level might be too long. Unlike Vita's other FPS games, these are not "bite-sized" missions at all. Given how lengthy they are, it's a good thing that Vita has such an excellent sleep mode. There are some concessions made to increase replayability. For example, once you complete a mission, you'll unlock "special contracts" that will have you performing specific actions during replays. You can also go for a higher score. Every action, every kill earns you cash--and cooler kills (like stealth takedowns and headshots) give you a lot more money. Stylish play will help you earn more money and unlock better gear faster. Best of all, money earned in single and multiplayer will go to the same pool.
The brief time I've spent with Killzone: Mercenary is, for better and for worse, a more robust experience than any other FPS I've played on Vita so far. Given the dearth of software on Sony's handheld, many are likely to settle for whatever they can get their hands on. However, Guerrilla Games' next has the potential to be much more than adequate-enough--it could even be great.
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