I've almost got target lock when the enemy banks sharply to the left. "Sonofabitch!" I shout, pouring on the speed and rolling my plane, leaning hard to the side, as if my body movements will make the craft more responsive. The toilet seat creaks in protest.

Its protests go unheard. There's 30 seconds left on the clock, and the four flashing red indicators converge on my target. Missiles fire in a graceful arc toward my respected foe. I suddenly realize I'm humming Kenny Loggins' Danger Zone. That's right, baby. My bathroom is now officially the Danger Zone.

As you may have worked out, I'm having a bit of a problem with MetalStorm Online, Z2Live's online aerial combat game for the iPhone. I can't stop playing it, and I can't seem to get it through my head that the leaning from side to side, forward and back, isn't actually helping me maneuver. The responsive tilt controls work quite well on their own. I'm just getting caught up in the action.

Think of MetalStorm Online as a bite-sized version of Namco's Ace Combat series with a focus on quick and dirty online play. Select your plane, arm yourself with weapons and ammo, and you're ready to fly the unfriendly skies. The accelerometer controls movement; buttons control speed, missiles, and machine guns; and finger-swipes perform special evasive maneuvers, perfect for dodging missiles.

The game currently features only two modes. In Survivor Mode the player takes on wave after wave of enemy planes either by himself or with a friend via online cooperative play.

The real action is in Versus Mode. Two players, two planes, and two minutes to kill each other. Speedy matchmaking and the two minute limit makes MetalStorm Online the perfect dose of bathroom break gaming.

And hey, it's free, to an extent.

While the initial app purchase costs you nothing, unlocking the best planes and weapons in MetalStorm Online will likely cost you some coin. You can earn in-game credits by playing, but the amount you earn rather paltry. The basic planes in the game run 1,000 credits. That's the equivalent of 20 coins, which can be purchased for $.99.

Even when you upgrade your missiles you are really only buying a limited stock, downgraded when you run out of cash to replenish your supply. To excel at MetalStorm Online you either need to be very good, or have some spare cash laying around. Still, a free 3D aerial combat game that plays this well and looks this good might be satisfying enough on its own to keep you from reaching for your wallet.

And if you do, make sure you wash your hands first.

MetalStorm Online [iTunes App Store]