Alone but strong

This is a single player first-person action shooter. Easy and uncomplicated to play. Not so much stealth and sniping but more of speed and action. 19 levels. A relatively open world allows the player to choose any path. Shoot all enemies or just run through the level. A mixture of realistic environment and unrealistic enemies. The humanoid enemies are zombies and biomechanical mutants. A large mech fires homing missiles. Another mech is armed with machine guns. The humanoid enemies chase the pla...