24 games ranked by how much the tags Steam players vote on them overlap with Deep Blue Fantasy's. A rare tag counts for far more than one that sits on half the store, and popularity never moves a game up.
What they share most: Submarine, Underwater, Steampunk, Lovecraftian, Simulation, 2D.

1·We Need To Go Deeper
81% match · Submarine, Underwater
86% of 6,044 reviews positive

2·Barotrauma
75% match · Submarine, Underwater
94% of 90,171 reviews positive · 3,563 playing

3·Reveal The Deep
74% match · Underwater, Lovecraftian
83% of 1,447 reviews positive

4·Iron Lung
74% match · Submarine, Underwater
92% of 11,311 reviews positive

5·World of Diving
73% match · Underwater, Exploration
49% of 766 reviews positive

6·Hungry Fish
73% match · Sailing, Underwater
78% of 32 reviews positive

7·Swallow the Sea
73% match · Underwater, Submarine
97% of 2,464 reviews positive

8·Feed and Grow: Fish
72% match · Underwater, Early Access
78% of 21,816 reviews positive

9·Beyond Blue
72% match · Underwater, Exploration
88% of 1,520 reviews positive

10·AquaNox
71% match · Underwater, Submarine
72% of 404 reviews positive

11·Horizon's Gate
70% match · Sailing, Turn-Based Combat
95% of 1,269 reviews positive

12·SUNLESS SEA
70% match · Lovecraftian, Steampunk
83% of 9,569 reviews positive

13·X-COM: Terror From the Deep
69% match · Underwater, Turn-Based Strategy
91% of 946 reviews positive

14·Into the Breach
68% match · Turn-Based Strategy, Rogue-like
94% of 22,457 reviews positive

15·Stoneshard
68% match · Rogue-like, Turn-Based Combat
75% of 35,763 reviews positive

16·Black Skylands: Origins
68% match · Underwater, Steampunk
86% of 543 reviews positive

17·Empire of Angels IV
68% match · Turn-Based Strategy, Turn-Based Combat
66% of 444 reviews positive

18·Darkest Dungeon®
68% match · Turn-Based Combat, Lovecraftian
92% of 162,876 reviews positive · 4,274 playing

19·Silent Hunter®: Wolves of the Pacific
68% match · Submarine, Underwater
70% of 1,145 reviews positive

20·Quasimorph
68% match · Turn-Based Combat, Rogue-like
83% of 8,378 reviews positive

21·Nantucket
68% match · Sailing, Strategy
79% of 883 reviews positive

22·Dangerous Waters
68% match · Submarine, Sailing
78% of 405 reviews positive

23·Sunless Skies: Sovereign Edition
68% match · Steampunk, Lovecraftian
84% of 3,482 reviews positive

24·Sandwalkers
68% match · Turn-Based Combat, Turn-Based Strategy
75% of 566 reviews positive · 8 playing
The closest matches to Deep Blue Fantasy on Steam are We Need To Go Deeper, Barotrauma, Reveal The Deep, Iron Lung, World of Diving. They rank highest because their Steam community tags overlap most with Deep Blue Fantasy's, and shared tags include Submarine, Underwater, Steampunk.
Every game is described by the tags Steam players vote on it. Rare, specific tags such as Submarine, Underwater, Steampunk count far more than catch-all ones like "Indie" or "Singleplayer", and each game is scored on how closely its whole tag profile matches Deep Blue Fantasy's. Popularity never affects the ranking.