Translating a video arcade game into an audio game is never easy. In many of them, the layout on the screen requires that you see everything going on, so you can make the right moves.
As an example, consider PacMan – an arcade game that was popular in 1980. Using a joystick, you move around the screen through an easy maze, trying to avoid bad guys; when you eat a power pellet, the bad guys turn into ghosts and you can eat them. You can only move up, down, left or right, and the screen wraps top-to-bottom, left-to-right. Turning PacMan into an audio game means you need to identify where in the maze you are, where the four bad guys are, where the power pellets are. And except for the power pellets, everyone is always moving.
An easier game is Space Invaders. There are 10 or more rows of invading spaceships that move left and right, slowly working their way from top to bottom of the screen, dropping bombs on you. Your task is to fire a laser cannon at all of them, to prevent them from reaching your planet, while not getting hit by the bombs.
In this game, you need less information to win. You need to know if there’s an invader above you, so you can shoot at it. You also need to know if you are about to be hit by a bomb, how far away the closest invader is, and how many rows of invaders are left. Using separate sounds in your left and right ears, switching between a man’s voice and a woman’s voice, and having about six more sounds, is enough to make the game playable and realistic.
Here’s how we turned it into an audio game:
As the invaders move left or right, you hear a click; when an invader hits the left or right edge, you will hear a boing, and all invaders move down a little, and then start moving in the opposite direction.
When there are 15 or fewer rows for the invaders to move down, a man tells you how many rows before the invaders reach your planet. Until the invaders get close to your planet, the man remains quiet.
A woman tells you how many invaders are above you laser canon; if none, she says zero; otherwise, she’ll tell you how many invaders are above you. To move your laser cannon left and right, tilt the phone left and right. If she says there are many invaders directly above you, fire away.
Blindfold Space Invaders is designed to be played with just your left or right hand, leaving your other hand free to perform other gestures when needed. If you are right handed, cradle the phone in your left hand, with the base of your thumb on the left edge, and your other fingers wrapping the bottom of the phone to the right edge, and fire your cannon by tapping the screen with your thumb.
Just like the video game, the invaders move faster and faster as they get close to your planet. It’s an addicting game, and you can download it here: