Thunderground

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.