BrainWave 2 is a single player shareware game that combines the control system of Space Invaders with the swooping enemy formations of Galaxian. It is a sequel to Dexterity Software's BrainWave.

Once again nanobots are attacking the player's brain and the player's imagination has created a ship with which to fight them. Like its predecessor this is a keyboard controlled game with the arrows moving the ship left / right and the space bar firing the ship's weapon. These is no up/down movement.

When a wave of nanobots has been cleared the game displays the player's score before presenting the next wave. Destroyed enemy ships leave behind power crystals which, if collected, can be used to buy power ups such as more effective weapons, shields and special features before the next wave commences. With each successive level the enemy ships also evolve, getting power ups of their own making them harder to hit and giving them better weapons. The player starts with three lives, new lives are added for every 300,000 points scored. When a life is lost all the crystals that have been collected are lost.

The full game has three scenarios, only one of which is available in the shareware release. Some weapons and features are also available only in the registered release.