 The series follows the adventures of protagonist Sam "Serious" Stone and his fight against the forces of the notorious extraterrestrial overlord Mental who seeks to destroy humanity.Enemies spawn frequently and attack in large waves from across the game map, and the player is intended to dodge their projectiles and charges by jumping and strafing rather than by taking cover.Health and armor are non-regenerative on most difficulty levels, and instead are replenished with the health and armor packs which are littered throughout the game.