I love the creativity on this! Great atmosphere setiting with the narrative and foreboding music! Amazing that you can tell such a compelling story with just a few scenes. The shader on the graphics and the font used really sets the Victorian steampunk vibes!
Sadly, I didn't make it to Tartarus, I failed every, single, encounter rolls haha. The game would really be complete if there was some minigame component to each encounter, or if the remaining crew interacted with the outcomes.
Other small QOL improvements I can think of would be a engine rumbling noise to indicate that the sub is moving, Otherwise, a really good entry!