Threshold

Threshold is a typical shoot 'em up in which the player's spaceship is placed at the bottom of the screen, where he has to fend off the enemies. If the player misses an enemy and it reaches the opposite side of the screen, it reappears on the other side of the screen. This continues until the player has destroyed all the enemy ships and the game moves on to the next phase, in which the enemies approach in a different attack pattern. Of course, contact with an enemy projectile or an enemy itself results in the loss of a life.