Games like Nettle
Games like Nettle include RimWorld, Terraria, Oxygen Not Included, Stoneshard, and No Man's Sky. We matched them by the tags players give Nettle on Steam (Strategy, Procedural Generation, Pixel Graphics, Singleplayer, and Survival): closest matches first, and among equally close ones the better-known games.

RimWorld
Shared: Strategy · Survival · Colony Sim

Terraria
Shared: Survival · Pixel Graphics · 2D

Oxygen Not Included
Shared: Survival · Colony Sim · Singleplayer

Stoneshard
Shared: Strategy · Pixel Graphics · Survival

No Man's Sky
Shared: Procedural Generation · Survival · Exploration

Core Keeper
Shared: Pixel Graphics · Survival · Exploration

They Are Billions
Shared: Strategy · Colony Sim · Survival

The Escapists
Shared: Strategy · Pixel Graphics · Singleplayer

Cosmoteer: Starship Architect & Commander
Shared: Singleplayer · Strategy · 2D

Frostpunk
Shared: Strategy · Survival · Colony Sim

Aliens: Dark Descent
Shared: Strategy · RTS · Singleplayer

Banished
Shared: Strategy · Colony Sim · Survival

Going Medieval
Shared: Strategy · Colony Sim · Survival

Subnautica
Shared: Survival · Singleplayer · Exploration

Castle Story
Shared: Strategy · Colony Sim · Survival

The Long Dark
Shared: Survival · Singleplayer · Exploration

Forager
Shared: Pixel Graphics · Survival · 2D

Wall World
Shared: Pixel Graphics · Strategy · Procedural Generation

Rain World
Shared: Survival · Pixel Graphics · Exploration

The Forest
Shared: Survival · Adventure · Singleplayer

Dawn of Man
Shared: Strategy · Survival · Colony Sim

Space Haven
Shared: Strategy · Survival · Colony Sim

Until We Die
Shared: Strategy · Pixel Graphics · Survival

DAVE THE DIVER
Shared: Pixel Graphics · Singleplayer · Exploration