Really good simulator of UBoating. A ton of settings for finetuning just how casual vs hardcore you want it to be, lots of impressive mods. Only annoyance is not having the Steam workshop here, but there are ways to download mods from there to use with the GOG version.
This game is honestly cute in how small it is, especially compared to its sequel, but god damn you can see why it spawned an entire genre that continues strong almost 30 years later. It's so addictive. I highly recommend grabbing this before Blizzard delists it too.
This game is just amazing. It's a lot of fun running around the wastelands, doing quests and killing things, specially if you get some Energy Weapons. The interface of the game can be clunky (specially if you have a mouse that doesn't like to collaborate, like mine), the graphics, while kind of dated, still look nice and have a distinctive feel from other games. The gameplay is fun and feels rewarding. I reccomend.