[Continuing Gamasutra's 'Game Design Essentials' series, which has also included '20 Difficult Games' and '20 Open World Games', this fascinating installment examines unconventional control schemes, from Robotron through Crazy Climber to the Wiimote and Guitar Hero, with detailed design lessons for each concept.]

Stop for a moment and consider what it is that makes a game control well. It is not as easy a question to answer as you may think.

There is a theory that the controls of a video game should do their best to get out of the player's way. The interaction between the player's mind and the game world should be as simple as possible. The perfect controller, to this thinking, is something that would read minds and eliminate all possibility of confusion, other than that in the player's head. There would be no controls to learn, no buttons to press, and no fumbling with control pads. Input would be completely mental, and output would be a holodeck.

In the absence of such technology, controls should be standardized so a player can move from one game to another easily. They seek to develop a shared control language that applies across games: left stick moves, right controls camera, the major action button shoots, a secondary one jumps, shoulder buttons flip between weapons -- that kind of thing.

Every control style mentioned in this article speaks against this theory. Some present their own standards in its place, due to their being well-suited to their style of game; the dual joystick (shooting) style has been used in a few games itself, from the old classic Robotron: 2084 to Geometry Wars. Others really have no chance of ever becoming a standardized control scheme, but are okay with it. After Donkey Kong Jungle Beat, why would anyone else even care to make a platformer controlled entirely with the pressings of two buttons? But then, why would someone have cared to make it to begin with?

For some of these games, special hardware is needed to measure player performance in greater detail, so as to translate it into game terms. In the Golden Tee games, rolling the trackball further and faster makes for a stronger shot. Other games use special controllers to accentuate the game experience. Guitar Hero naturally does this to help the player feel like a rock star, and the bicycle-powered arcade game Propcycle is perhaps the closest we will ever come to experiencing human-powered flight.

The purpose of this article is not to describe the games themselves, unless it is important to do so to explain what makes its control scheme interesting, or if the style is mostly relevant to only one game. Because it's concerned with games that purposely do things in a non-traditional manner, there's an unusually large representation from arcade developer Atari Games on this list.

Finally, again, although the list is numbered, this should not be taken as a list of the "most" unusual control styles ever seen in games. Attempting to make such lists will always make some folk unhappy. I know I'm never happy with them. These games are given as examples. Some are obvious, and some push the limits of the theme. That is the point. The idea is to give you ideas for your own project, and to show some notable successes, and maybe failures too.