Borderline

Borderline is a 1981 arcade game by Sega. The player controls a Jeep and has to destroy enemy refineries. Borderline was reissued later in the year with slightly altered graphics as Star Raker. It was a launch game for the SG-1000, and converted for the Atari 2600 under the name Thunderground, released by Sega's home division.

There are four stages with different gameplay. The first stage is a vertically scrolling shooter: the player can move the Jeep in all directions, shooting at enemies that try to destroy it by collision; the goal is simply to survive. The other stages share a different gameplay concept: the player has to navigate the Jeep towards enemy refineries and destroy them all. Enemy tanks will spawn indefinitely, trying to stop the Jeep. Parts of the stage are covered by bushes, and the Jeep has to furrow through them before advancing. In the third stage rockets can be picked up for bonus score. In the fourth and final stage the sole refinery is well-protected and shoots missiles at the Jeep.