Depthcharge

Depthcharge, known in Japan as Depthbomb (ディプスボンブ), is an arcade game released by Gremlin Industries for VIC Dual hardware in 1977, and published by Sega in Japan and by Gremlin Industries in US.

Depthcharge is a single screen action game where the player is in control of a destroyer and has to destroy as many submarines as possible. The game is viewed from the side with the player being able to move the destroyer left and right along the surface of the sea. Beneath, submarines (up to four at a time) appear at different depths and at different speeds that the player has to destroy by launching depth charges from the left or right side of the ship. Each submarine has a number that indicates its point value. A maximum of six depth charges can be used at a time. Submarines release mines that float to the surface and explodes. If the destroyer is hit by one the player's score is cut in half.

The game lasts 90 seconds and the aim is to get the highest score within that time. If a score is higher than 500 points the time is extended with 45 seconds.