When it came out in 2007 in Japan, Square Enix's The World Ends With You used the Nintendo DS's dual screens and that system's lower touchscreen to great effect. It's no surprise then, that the company has re-released the game for iOS systems with their touchscreens. The game's iOS version, dubbed Solo Remix, does what a good port should – it retains all the flavor of the original while adapting itself to its new home.

Solo Remix is essentially the same game that garnered critical acclaim back when The World Ends With You originally released here in the States in 2008. Set in modern-day Tokyo, Neku and the friends he begrudgingly adopts must overcome an invasion of the Reapers (chuckle) and their minions known as Noise. I wasn't enraptured with the game's story or its annoyingly Japanese characters, but with the depth of the game itself.

Players collect and level up pins that enable specific attacks, upgrades, and other benefits. These are dropped in battles, but can also be bought in stores around Tokyo. The game not only has different areas of Shibuya you travel to, but a whole running economy based on which pins are most popular from certain stores in the area. The more popular a pin is at that moment, the more effective it becomes and vice versa. This also goes for clothes and other items you can equip on your character for boosts.

The fact that Solo Remix retains this infrastructure goes a long way towards making this a full-fledged iOS title and not just another slight distraction on the platform. The original game's dual-screen combat system was a big selling point, and Solo Remix does its best to adapt it to the single screen of iOS devices. I prefer the one on the DS, but this one has its advantages, and does not hamper my recommendation of this game regardless of where you play it.

Instead of you and your in-game friends simultaneously fighting foes on both DS screens, the action is relegated to a single screen. Your friends' attacks are enabled with your finger touches, and you alternate their attacks with your own to build up a synch percentage. Get a 100 percent or greater and you can unleash a Fusion attack. This replaces the Fusion/stars system from the original.

Although I miss the dual-screen battles of the DS game (and its ESP cards), iOS offers its own solution. You unleash a devastating Fusion attack by going to a separate screen and performing a quick minigame (which changes depending on which friend main character Neku is paired with at the time). Overall, iOS handles the different pin attacks well (performed by actions like poking, sweeping, etc. the screen), although it's a good idea to vary your pin loadout so you don't overlap similar, and possibly confusing, combat situations. Not doing so could even negate potential combo opportunities with your in-game friends because their attacks and yours might require similar touch commands.

Solo Remix also includes exclusive Twitter support. If you enable it you can populate the in-game world with the tweets and the game's Friend Cards from you real-life friends (and their tweets, too). It's a cool addition as you wander Shibuya and scan people's thoughts to see your friends' tweets populate the game. You can also fill it with tweets pertaining to any hashtag or topic you choose.

Solo Remix is available now for iPad 2 and iPhone 4 (and onwards) for $19.99 and $17.99, respectively. Each is sold separately and the game is not a universal app. Naturally, iPad 2's Retina display makes things beautiful, and performing the touchscreen battle actions and navigating the world are more comfortable on the tablet. However, the iPhone version is not hampered by its smaller screen. No matter which way you go, I definitely recommend checking this game out.