Rootwork

Inspiration

The wood wide web — the real, documented phenomenon of trees communicating and trading nutrients through underground fungal networks — has always felt like it deserved a game. Not a documentary, not a clicker, but a genuine management simulation where the player becomes the intelligence beneath the soil. Rootwork is that game.

What We Built

Rootwork is a Simulation & Management game for Meta Horizon Worlds in which the player inhabits a mycelium network growing beneath an ancient forest floor. By extending fungal threads (hyphae) through soil, you connect host trees, broker nutrient trades between species, and unlock biological upgrades called Mutations — slowly rebuilding a woodland ecosystem fractured by drought and disease.

The core loop runs on three tiers:

Grow — drag hyphae threads across the forest map to reach new tree roots and mineral deposits
Trade — passive nutrient exchange activates automatically between connected trees, generating Symbiosis Points
Evolve — spend Symbiosis Points on a Mutation tree that permanently changes how your network behaves

How We Built It

The game is designed for the Meta Horizon Worlds Desktop Editor using TypeScript as the sole scripting language. The economy simulation (nutrient flow, trade routes, symbiosis accumulation) runs server-side, while all UI panels — resource bars, mutation cards, trade route lists — run locally per player via UIComponent scripts. The visual network threads are cylinder entities managed through an object pool, positioned and rotated at runtime using Vec3 midpoints and Quaternion.lookRotation. Player network state persists across sessions using Player Persistent Variables (PPVs), with Forest Health stored in World Persistent Storage.

Challenges

The central design challenge was making a passive, slow-burning economy feel tactile and immediate on a mobile screen. The solution was to make every gesture — dragging a thread, tapping a root, watching nutrients pulse along a route — feel consequential rather than abstract. The visual language (bioluminescent threads, earthy palette, glowing nodes) does the heavy lifting: the network is always the hero of the screen, never the UI around it.

A technical challenge was the thread drawing system. Stretching and rotating cylinder entities between two arbitrary node positions in 3D space required careful handling of the animated motion type constraint in Horizon Worlds — entities must be declared animated at edit time before their transforms can be updated at runtime.

What We Learned

That the most interesting design space is often the one nobody has claimed yet. Underground ecosystem simulation as a mobile game genre doesn't exist — and the reason it doesn't exist isn't that it's a bad idea, it's that nobody tried. Rootwork is the attempt.