Borderline

Borderline (ボーダーライン, Bōdārain) is a 1981 vertically scrolling shooter maze game developed and published by Sega for Japanese arcades; it was distributed in North America by Sega/Gremlin and in Europe by Karateco. The player controls a jeep and has to destroy enemy refineries. There are four stages with different gameplay. The first stage plays like a vertically scrolling shooter; in the second stage, the player maneuvers the Jeep through underbrush, and enemies can only follow on its path, a concept later found in Namco's Dig Dug (1982).

Borderline was reissued later in 1981 with slightly altered graphics as Star Raker. In 1983, it was converted for the Atari 2600 under the name Thunderground by Sega's home division, making it one of the last games Sega released as a third-party developer for Atari. It was also ported to Sega's own SG-1000 console in 1984. The SG-1000 and 2600 ports received positive reviews from critics.