There's a big problem with video games on Apple's iPod Touch and iPhone. There's no joystick to control them with, no directional pad to press. Just glass to touch and a device to tilt. At last, there's a strange solution.

Prepare to welcome to the world the two-directional virtual joystick, a virtual slider rendered on the bottom left corner of a major upcoming iPhone game, Ubisoft's Assassin's Creed II Discovery. It is used to move the game's hero, the Renaissance Italy assassin Ezio de Auditore through his 2D, side-scrolling world. Under the player's thumb, the slider "moves" left, "moves" right and ... that is all. (We recently previewed the game, slider and all.)

In the logic of technological advancement, the two-directional virtual joystick makes no sense. Since the days of Atari joysticks and arcade machines, people have been able to move gaming characters in four or even eight directions. Pac-Man needed to support movement in four directions. Galaga kept players moving in just two directions, but the stick at least tilted more ways than that. Super Mario Bros supported left, right, up and down on a four-directional "d-pad" on the original Nintendo controller. And in the 90s, gaming consoles began to use analog control sticks that supported leaning and nudging in dozens of directions.

Joysticks and directional pads and analog sticks have proven so essential to video games that, for a year, developers of games on the joystickless, pad-less, stick-less iPhone have been rendering virtual versions of the things in the lower left corners of their game screens. They've been asking gamers to go with it, to pretend and to tolerate the twin aggravations of one's thumb winds up covering part of the screen and the fact that you can't feel virtual control sticks.


So much for the opportunity to admire the big screen of the iPhone in its entirety or to have nuanced directional control of a game on it.

Here are three examples, Zenonia and Dungeon Hunter, two popular iPhone games, along with the iPhone version of Sonic: The Hedgehog, trying to make do.


The people making Assassin's Creed II Discovery for the DS considered faking it too. "Quite literally we just tried it all," the game's producer, Ben Mattes, told Kotaku in an interview. A producer from game giant Ubisoft, he worked with handheld gaming specialists Griptonite Games to create Discovery. "We tried a sort of virtual analog stick for the left thumb, [but] it meant your thumb had to cover even more of the screen real estate." Mattes had taken out a ruler and made some "rough calculations." He determined that a virtual stick, covered by the player's thumb, obscures 18% of the game's screen.


His team tried the other clumsy solution: Maybe let the players tilt the iPhone left and right to make the character move?

We tried the accelerometer-based [style]," he said. "Tilt it left to run left, tilt it a little bit left to walk left, tilt it right to run right, tilt it a little bit right to walk right. That sucked because you would have to tilt your head a little bit in order to keep your eyes level with the screen. Or you would risk not seeing the enemies you were trying to sneak up on. For a slower-paced game that type of accelerometer control might work. But for a game as fast-paced as Discovery that was just not going to happen."

Instead, the developers of Assassin's Creed II Discovery made — perhaps invented — the two-directional virtual control stick. Bear in mind how radical this was, not just to ignore the 30-year technological trajectory of control stick design but to ignore, well, themselves. The team making Discovery had already developed and released the game for the Nintendo DS. On that system, it supported the system's directional pad, all eight directions of it.


It turns out, eight directions was six more than were needed. Assassin's Creed II Discovery's hero does sometimes need to do more than move left and right. He sometimes needs to climb a wall or lower himself down. It turns out that right and left can accomplish that, if you think of a two-directional stick not as something that moves a character left and right but forward and back. A little move of the slider to the right would have Ezio walk. A move further to the right would make him run. If he faced a wall, he'd climb it. To lower himself back down, the slider needed to be moved to the left. (There's also a virtual jump button on the right side of the screen, for, well, jumping.)

"When we dropped it down to just this left and right slider, we were able to get very nuanced subtle control of Ezio and still get all of the controls we needed in the game," Mattes said. "We didn't need the up and down and we still had all the gameplay mechanics we wanted."


The bonus effect was that the slider took up very little room on the screen. A player's thumb, using it, would occupy far less than 18% of the screen.

There's a problem with the Assassin's Creed breakthrough, of course. The game Mattes' team made is a side-scroller. Up and down really isn't that important in a side-scrolling game, as opposed to, say, Zenonia and Dungeon Hunter, the games pictured above that are played from an overhead perspective. For those games, the ability to move in all directions of a compass still seems essential. Or, well, is it?

No developer has made a game that used a two-directional stick in a long time. There's been a breakthrough here, and welcome relief to gamers whose iPhones just haven't been able to fake the feel of a game controller well enough. Credit to Mattes and the teams at Ubisoft and Griptonite Games for trying something new, something simpler, something streamlined.


Two directions might be more of the right direction than anyone ever considered before.