Access Invaders is a fully-functional game, developed by the Human-Computer Interaction Laboratory of ICS-FORTH in close cooperation with the Centre for Universal Access & Assistive Technologies, in the context of the Universally Accessible Games (UA-Games) Activity. The game can be played in Windows and GNU/Linux. It can be concurrently played by individuals with different abilities and preferences, including people with disabilities, e.g., low-vision, blind and hand-motor impaired.

The game is highly customizable and supports the creation and use of unlimited user profiles. Each game parameter can be customized both based on the player's profile and the current game level. An unlimited number of players is supported. The game can be played using the keyboard, the mouse, a joystick, and one, two or three switches (or even more). It also features spatial (3D) sound and a screen reader (for presenting textual information), so that it can be played by blind people too.

In the latest research prototype of the game, two more input techniques have been added:

1. Vision–based gesture recognition: a standard web camera is used to track hand movement and recognize palm and finger gestures. This module was developed by the Computational Vision and Robotics Laboratory (CVRL) of ICS FORTH.
2. Musical input: individual musical notes, irrespectively of the instrument used to produce them (e.g., by whistling, knocking a spoon against a glass, playing the guitar or the piano, or even singing) are recognised and mapped to game controls .

 

Basic profile

Single switch profile

 

 

X-Large profile

Non-visual profile

 

The game was developed in C++, using:

• SDL: low level, cross platform, graphics and input library (http://libsdl.org)
• OpenAL: cross platform, 3D API for spatial sound (http://www.openal.org)
• Festical lite (aka Flite): cross platform, runtime speech synthesis engine (http://www.speech.cs.cmu.edu/flite)
• FreeType: software font engine for true-type font rendering (http://www.freetype.org/index2.html)
• OGG vorbis: audio encoding and decoding technology (http://www.vorbis.com)

The Access Invaders game was developed using the Accessory Game Engine of the HCI Laboratory for animated 2D accessible games, with a software architecture and overall development management by Anthony Savidis. Programming by Yannis Georgalis.

Game design amendments and extensions over the classical genre and accessible interaction design by Dimitris Grammenos.