Copyright 2022 James Teh, based on the Eureka A4 game by Geoff Shang
Version 20
You will first hear your position, represented by a pitched beep. When an alien arrives, you will hear a second beep. The beeps alternate between your position and the position of any aliens.
Move your position left or right with the left or right arrow keys to match the pitch of the alien. Press space to fire before they hit the ground and destroy you! If you are using a touch screen, tap the left of the screen to move left, the right of the screen to move right and the centre to fire. If you are using a touch screen reader, you will need to turn it off after starting the game so the game can receive the taps directly. For either keyboard or touch screen, You can hold your finger down to move faster.
Most aliens remain stationary. However, you will occasionally encounter commanders which move from left to right, increasing in pitch. You don't lose a life if you don't hit a commander, but you get bonus points if you do.
As you level up, you must confront more aliens at once and you will encounter more commanders. In the higher levels, the game will speed up.
If you are using a screen reader, you can announce your score at any time during the game by pressing s.
Every 200 points, you can gain an extra life, but only up to a maximum of 5 lives.
If you are using an iPhone on speaker, ensure your phone is not set to silent.