Skill game.
Seawolf is a remake of my Amiga game of the same name from 1991.
Dive into the underwater caves and traverse them. Collect crystals in the process. The submarine starts automatically. You can only move forwards, upwards and downwards. Your oxygen supply is limited. If you brush against the cave wall or touch thorns, you will lose oxygen. When the oxygen supply is exhausted, your submarine implodes and the game is lost. Can you make it through all 10 levels without destroying your submarine?
With Highsocre.