Just wanted to get a few clarifications:...

2) In terms of switch gaming and multiplayer, how does switch gaming handle multiple player input? (meaning other than "spacebar" which other buttons should I be using?)

I'm not officially linked to the competition, but I've tried to post the best accessibility guidance I can here: http://switchgaming.blogspot.com/2009/12/gamma-iv-one-switch-help.html - which includes some advice for multi-player accessibility standards. Hope that helps?

It says at the link's page that the xbox A-button is the "button 1", but I don't know if it's the first index (i.e. Joy button 0) or the index number one (i.e. Joy button 1)

...or, I could bind all buttons to the same single action, just in case, if that's allowed.

For a PC from the Joystick properties utility the Xbox 360 joypad buttons are indicated as:

A = button 1
B = button 2
X = button 3
Y = button 4

LB = button 5
RB = button 6

BACK  = button 7
START = button 8

LEFT THUMB STICK BUTTON = button 9
RIGHT THUMB STICK BUTTON = button 10

An easy way to test this is to connect almost any compatible joypad/joystick controller to your PC. Go to "Devices and Printers" (via the START menu and for XP/Vista via the Control Panel). Next access your connected joystick and open up the "Game Controller Settings" or properties. If you press "A" on an Xbox 360 controller - you should see the on-screen button 1 indicator illuminate. Almost all joysticks/joypads will have a button mapped to 1.

There's nothing in the rules to stop you mapping your single control to all of those buttons. Nor also the SPACE BAR and LEFT MOUSE CLICK to make your game compatible with most accessibility switch interfaces. So long as they all do the same thing.

Very excited about Gamma IV. Thank you for running this!

For entrants interested in making their games accessible to the broadest range of players please take a look here:

http://switchgaming.blogspot.com/2009/12/gamma-iv-one-switch-help.html

Alongside some basic guidance, there's examples of existing one-button games and more that may help people trying to think of something original. GOOD LUCK ALL!

Barrie Ellis
www.OneSwitch.org.uk and the IGDA Game Accessibility Special Interest Group