Frenesis is a 40 level game where you have to protect a cross in the middle of the screen stretching to the edges of the screen from waves of aliens. To destroy the aliens as they move towards the cross from all angles, you have a Statron which is a line stretching to the edges of the screen, made up of arrows that can either move vertically or horizontally along the screen. When you move the Statron the arrows point in the direction of travel and if the end of the arrows hit an alien moving in the opposite direction then it is destroyed. You have a set quota of aliens to destroy within a time limit but if an alien hits the cross then the quota goes up and if the timer runs out before the quota is fulfilled then you lose one of three lives. As well as the main aliens there is another type of alien that moves in three stages and can only be destroyed on the final stage. You also have a smart bomb that can be activated but you are limited to a certain number depending on the level but destroyed aliens don't go towards the quota. On certain levels you have your lives topped up back to three and the joystick is used to control the Statron.