While you wait for Subnautica 2, here's a moody Bioshock-esque strategy game in which you can put Big Daddies on crabs

Dave Jones' Unlocks

As Subnautica 2's early access launch approaches, my mind inevitably drifts to videogames that explore the pleasures and horrors of the deep blue. Tides of Tethys is one for the Jules Verne fans amongst you, with perhaps a pinch of Warhammer 40,000. It's an underwater strategy roguelite with city-building elements in which you guide troupes of bathynauts around procedurally generated ocean floors.

You'll need to expand your modular outposts, ensuring your Knights have oxygen and power and food, while dealing with increasingly unfriendly aquatic beasties. I thought the giant crustacean I slew in the just-updated demo was an unfriendly beastie, but then I got a Steam Achievement for killing a harmless creature. I do hope this won't have ramifications. I hope that giant crustacean doesn't have a mother. Hang on, it looks like I can turn crustaceans into valiant steeds! Don't eat me, crab mum - I promise I will be nicer to invertebrates in future.

I'm rooting for Tides of Tethys, though I'm mixed on the demo. It's a slow game in the first hour, with a lot of tutorial to digest. The user interface is gunning for baroque, with curly gold fonts and such, but it has landed on the side of unwieldy. When you group-select Knights, it opens a character menu that obscures most of the scenery – the knights do, in fairness, have a lot of stats and buffs to keep track of.

It's a shame, because the scenery is attractive, if a bit lumpish and oversaturated. There's a fog of war feature that looks like a mountainous oil spill, oozing back from your headlamps. The sands are sprinkled with flora that shrinks and responds as you trundle past. Your initial outpost is dwarfed by enormous curls of coral; I hope I get to build on those. True, a lot of it is just there to be drilled apart for resources, but I came away moderately enchanted. Your Knights themselves resemble Bioshock's Big Daddies and Sisters. They have a certain amount of agency, gathering resources unprompted and heading to oxygen tethers when they're feeling a touch asphyxiated.

I liked Tides of Tethys most when night fell, and the screen became a mass of shadows and fitful bioluminescence. In general, if developers Black Rust can clean up the presentation a little, they have the makings of something engrossing here. People who don't get on with Verne might prefer Life Below, a city builder inspired by coral reefs.