Games like Siegeturtle
Siegeturtle. These games share the most with it, and each one says why.

Mushies!FeaturedComing soon
Also prestige
Click the big mushroom, hire worker shrooms, build houses and dig underground in a cozy pixel-art mushroom village. Over 85 upgrades and a Wisdom prestige loop.

Shelldiver
Also ocean, animals
An elderly turtle pilots a submarine to catch jellyfish and salvage ocean junk, selling the haul to upgrade gear and dive into deeper biomes.
98% steam
Desktop Defender
Also auto battler, prestige
A lone tower in the corner of your screen holds off waves while you work, dropping gear to equip and resetting runs for permanent ascension upgrades.
92% steam90% idle
Joyquarium
Also ocean, animals
Raise fry until they are big enough to sell, keep adults in the tank for steady income, and open packs to unlock 144 species. An auto mode lets the tank run on its own.
97% steam70% idle
Desktop FishingDormant
Also animals, ocean
A frog in the corner of your screen fishes while you work, catching 50+ species with shiny variants and unlocking new spots and outfits.
91% steam90% idle
Fantasy Aquarium
Also ocean, animals
Breed fish across themed tanks and choose between keeping them for steady gold or trading them in, with ambient music for working.
85% steam
Shark Incremental
Also ocean, prestige
Grow a shark, eat fish, go deeper. A shiny, fast, well-paced modern idler.
4.5★ galaxy60% idle
Under the blue horizon
Also ocean, animals
A small aquarium sits on your screen beside other windows. Feed fish, turn their droppings into currency, and hire crawfish and jellyfish helpers to expand the sea.
82% steam90% idle
Swarm Simulator: Evolution
Also animals, prestige
Hatch larvae into drones and ever bigger bug units, sacrificing smaller ones and ascending repeatedly to grow a galaxy-scale swarm.
78% steam
Bounty Below
Also roguelite, prestige
Recruited units mine ore for you to smith into gear, while you can dive into a twin-stick roguelike dungeon for extra ore. Includes an upgrade tree and prestige.
80% steam70% idle
PC FISH: Taskbar Aquarium
Also ocean, animals
Raise and breed fish in a desktop aquarium, discover rare traits among 450+ fish and decorations, and trade on the Steam Market.
78% steam90% idle
Orc Incremental
Also auto battler, prestige
Draft orc units and totems from cards, set formations and cast spells as your warband fights on its own, ascending for permanent bonuses.
76% steam
Incremental Epic Hero 2
Also prestige, auto battler
Six heroes battle automatically across a fantasy world while you upgrade nearly everything and juggle many prestige systems, with over 1,000 hours of content.
72% steam
Samawa Idle
Also roguelite, prestige
Pick and level towers against monster hordes, shaping runs with random gear, passives and a skill tree across two prestige layers.
68% steam50% idle
The Fly Devourer Tree
Also prestige, animals
Evolve a creature built to eat as many flies as possible, progressing through nine layers so far.
4.3★ galaxy
Critter Clicker
Also animals, prestige
Build a farm of mills, smithies, and horse tracks with a built-in autoclicker, then sell it to start over on a bigger one.
58% steam
Miseria
Also auto battler, prestige
Guide a party of damned souls deeper into an abyss as they fight automatically. Level stats, forge equipment and use the Reborn reset for permanent power.
58% steam
Idle AntDormant
Also animals, prestige
Grow an ant colony by assigning workers and expanding production of food and other resources.

Idle Ant 2Dormant
Also animals, prestige
The sequel to Idle Ant, a colony-building idle game with more resources and research to manage.

BITXOUpdated
Also animals, prestige
Care for a pixel virtual pet whose meadow produces motes for upgrades, evolve it through 46 forms and ascend it to found a stronger dynasty.

Animal Warfare: Idle BattlerUpdated
Also auto battler, animals
Assemble an army of animals and send them into automatic battles across hundreds of campaign levels.

Tap Tap Fish - AbyssRiumUpdated
Also ocean, animals
Fill an aquarium with fish and whales that gradually grow the tank with little effort from you.
75% idle
Idle Fish 2: Fishing TycoonDormant
Also ocean, animals
Catch fish and upgrade your boat and fisherman to haul in rarer species.

The ArmyDormant
Also auto battler, roguelite
Upgrade an army of archers, wizards and healers, starting each round stronger after every defeat.