Turmoil (PC / Mac / Linux) - Steam - Digital Code

The player controls a space ship which is trapped in an area consisting of seven tunnels which are connected by a vertical shaft. Enemies are attacking the player from left and right and it is the objective of the player to destroy as many attackers as possible using the shaft. You can't, however, hover at one spot for too long since an invincible enemy will appear, forcing the player to change positions eventually.