[Editor Update: It seems the iCade support is not 'official' - that is to say, without modifications, physical controls are not yet available for METAL SLUG 3. Hopefully this can be added in a later update.]

If there's one game most responsible for causing me to waste my time at an arcade, it's probably NFL Blitz, but in a close runner-up is the METAL SLUG series in all of its incarnations. No matter which version or where I see it, I'll pump credits in to it. There have been many pretenders to the throne on the App Store, and even a few games bold enough to completely steal art assets, but the real-deal has finally arrived with METAL SLUG 3 thanks to DotEmu and SNK PLAYMORE.

However, before you jump straight on to the App Store in an almost knee-jerk twitch, be warned, this is a brutally challenging game and all the more so thanks to controls that could be best described as 'spotty'. If you happen to have an iCade, you're in luck as it's reported to be compatible, and all downsides related to controls can be ignored - jump in and start shooting away.

For everyone else, a configuration screen can be used to set the controls to your liking, but whether you play on a small or a large screen, it's difficult, bordering on impossible to replicate the same snappy response of an 8-way joystick and large buttons. As such you'll be feeling the cold-clammy grasp of death over and over, though you can always continue (albeit losing bonuses for rescuing POWs in the process).

If you need a couple reasons for biting the bullet and playing the game anyway, firstly you can succor yourself with the knowledge that Bluetooth co-op is available so you can nuke zombies and armored crabs simultaneously. Secondly, and more obviously, this is Metal Slug 3 - a game packed with oodles of features thanks in part to SNK's impending bankruptcy at the time of its creation.

One major improvement is the branching path system that allows players to complete a stage in one of several different ways, each leading to the same final boss, but providing unique challenges along the way. Better still, the vehicles the series is so famous for have been bolstered with a host of new ways to destroy the Rebel forces, be it from the back of an Ostrich or Elephant, or on a Rocket in space.

For those more concerned about presentation, the game has several options including video processing to smooth the pixels (my personal preference is to turn this off), and scanline emulation is also available in 50 and 100% options. Playing on the latest iDevices had the games running silky smooth, even when explosions and enemy corpses were flying around the screen.

Ultimately the pricey purchase will depend on how much you love the METAL SLUG series and whether or not you own an iCade or similar compatible device. It's easy enough to forgive the controls given the spectacular gameplay, but prepare to chew down continues like there's no tomorrow.