There are a lot of games available for the iPad, though MetalStorm: Online manages to rise above the glut of Angry Birds clones and match-3 puzzle games to offer something truly unique - an online aerial combat game.

There are few negatives associated with MetalStorm: Online, and many of those issues are completely subjective and may matter more to some players than other. Visually, the game shines among some of the best the iPad has to offer. Though it lacks some of Infinity Blade's finer details, I would still easier put it in the same league. The only massive negative - and again, this is completely subjective - is the lack of variety. There isn't much variety in terms of environments, but then again, you're usually searching for enemy planes. If you're looking at the ground, you're probably already dead.

Audio is just as vibrant. You've got a full compliment of combat sounds as well as an unobtrusive soundtrack. MetalStorm: Online also boasts in-game voice chat, which is great when playing with friends. It's a great feature, though you have to hunt for it, which is a silly oversight.

MetalStorm: Online is, for lack of a better explanation, Top Gun: Online. You're dropped into the cockpit of a fighter jet and offered the opportunity to take to the skies in both single- and multiplayer modes. You begin with a simple plane, machine gun and missiles, but quickly gain access to newer, better planes and weapons. How fast you gain these upgrades, however, depends on how much you're willing to spend.

Another of the big knocks against MetalStorm: Online is its dependence on in-app purchases. Although you can earn tokens by playing through matches, tokens are dolled out in a slow trickle. If you want quick access to everything you need to purchase token packs, which range from $1 - $50 per pack. It's completely possible to purchase every plane and upgrade by playing, though it takes a lot of dedication and time.

Although I'm willing to accept that in-game purchases are slowly becoming the norm, I'm not sure if I like how MetalStorm: Online handles the idea. I can see offering access to select planes, but nearly everything is dependant on you either grinding away for months or dropping a few bucks. I'd prefer a balance of the two, or at least other ways to earn tokens. I really like how Mooniz, another game built around in-app purchases, offers free token packs every week. It's a nice gateway incentive that gives players a taste of the token system. At the very least, I'd like to see the missile limit disappear. I can handle buying missile upgrades, but once purchased, I should have them permanently.

Gameplay is spread across two modes. In Survival Mode, you take on successive waves of planes either solo or with a friend. It's the closest MetalStorm: Online gets to squad-based combat and is a blast. You can also join in on Versus matches, where you take on another player. Online integration is seamless. It's easy to find and jump into matches and, with the exception of a random disconnect, they usually go off without at hitch.

In-app purchases throw off difficulty, though are only a major disruption in Versus Mode matches. Survival matches are rough, though even when you're outnumbered, the A.I. isn't incredibly bright. Unless two or more planes get right behind you and launch a simultaneous barrage of missiles, you can usually out-maneuver opponents. On screen indicators do a good job of pointing you in the right direction, though it is usually frustrating when you're trying to track down that one last plane in a wave.

Online matches are a different issue entirely. It is still possible to win a match if you decided to stick with the basic planes and weapons, though victories are usually a result of impressive skill or sheer luck. Of the two, I assign more wins to luck. It's hard to go missile-to-missile with players who've invested in in-app purchases. It's entirely possible to drop a chunk of money and instantly rocket to the top. I get the concept, but hate that it mars the experience for players who either don't want to or can't buy their way to victory.

MetalStorm: Online makes excellent use of the iPad's onboard gadgets. The HUD is pushed along the edge of the screen, allowing for maximum viewing range. Your plane is always placed at the middle of the screen, but once you get into larger encounters in Survival Mode, you'll want as much screen space as possible. Guns and missiles are assigned to buttons on the right side of the screen. Initially, I wasn't sure of the set up, but immediately took to the setup after my first aerial skirmish. Throttle and airbrakes are assigned to similar buttons on the left side of the screen, though for whatever reason I usually forget the buttons are there, which could explain some of my frustrations with tracking down enemy planes.

The absolute best element is the tilt-based steering. Understanding how to steer (or, rather, how much twist and tilt to put into motions) is one of the MetalStorm: Online's more challenging aspects, though like the fire controls, it is something you should adapt to quickly. The idea of tilting the iPad to may sound unappealing and not very practical, but it's more intuitive than you'd think. It's tempting to want to use wildly exaggerated movements, though the system is optimized to respond to the slightest of maneuvers. Even stuck in a crowded airport terminal, I was able to steer with little problem.

The only mechanics you're likely to overlook are the touch-based maneuvers. Slashing across the screen initiates an evasive roll while a vertical slash pulls a 180-degree turn. There are no on-screen indicators to remind you of the moves, so you might forgot you can do it. Those who remember, however, will have an easier time in both match types.

Although I'm not completely on board with the in-game purchases, I can't say MetalStorm: Online isn't worth the download. I may never buy anything, but I still had fun when I wasn't matched against players flush with cash. In-app issues aside, MetalStorm: Online is an easy recommendation and a great example of a mobile game done right.