This is a 6 maps wad I made, designed for both Singleplay and Cooprative (Up to 8 players). This wad's format is Doom 2(Hexen format) so it can run on GZDoom and Zandronum.
You may want to enable "Allow Freelook" in Gameplay setting. Some of under-water fight is deep and Freelook help you swim better.
Because there are some enemies in under but the game's auto aim cannot aim at them when enemies are exceed a slope of around 58 degrees. Beside that, I found no way to swim down without enable Freelook. Even with "Courch" button didnt do a thing. So be sure to enable Allow Freelook in Gameplay Settings.
I've been reworked this wad, adjust, fixing some bugs, made each map to be challenge for pistol start.
New Update with extra map: In the Storm of Bullets No need previous file, just download and play. The Only thing they fear is you MIDI version on youtube...
Full 6 maps pack WAD. Version: 1.0 The sixth maps music created by cheatsykoopa98