In Gosub you guide a submarine to the treasure without touching the walls. It was made using Batari Basic.

Changes:

+ added b/w, pal and ntsc support for mini-game (up until you start the game)
+ on your last life, the sub crashes and then goes to the game over screen.
+ sub slowed down in last black level. (is it slowed down enough?)

http://www.atariage.com/forums/index.php?showtopic=98009&st=225