🕹️ PS42017Guerrilla GamesVERY HARD

Horizon Zero Dawn rebuild deck

VERY HARD

You will get a good prototype. The product is what comes after.

The component system is the strongest argument on this list for prototyping a large game's combat — a couple of hundred lines that change every encounter. The agent will attach colliders once at load and never update them, and you will notice the moment your shots pass through a moving leg. Do not reach for a static BVH here either; anything that bakes a tree at load has the same bug wearing a faster hat. What a prompt cannot give you is the animation: a machine that does not move like an animal is a shooting gallery with extra steps, and that gap is most of Guerrilla's four hundred team-years.

Difficulty: VERY HARD · 4 of 5
First playable: A project
The original: 450 team-years
Released: 2017 · PS4
Genre: Action RPG

The one-shot build prompt

Build a single-machine hunting encounter. three.js plus a physics library. One arena, one robotic quadruped, a bow with three ammo types. No open world, no crafting tree, no story.

Requirements:
- The machine's body is a set of named components — two flank fuel canisters, a radar disc on the head, a mounted weapon on the back, four leg joints — each with its own collider, its own health and its own detach behaviour. A canister explodes for area damage. The radar disc, removed, halves detection range. The mounted weapon falls to the ground and can be picked up and fired until dry. A destroyed leg drops the machine's speed and staggers it.
- Get hit detection right or nothing else matters: component colliders must be re-driven from the animated bone matrices every physics tick. Raycasting against the bind pose is the default failure, and it will look like the game is lying to you. Render the colliders in a debug view.
- Concentration: hold to slow time to 25% against a draining meter, with the bow drawing at normal speed, so the meter buys precision rather than damage.
- Elemental ammo with per-component resistance: fire ignites exposed fuel, shock stuns for two seconds, tear does double damage to attachment points only.
- Placeable tripwires, and a trap the machine has to be lured across.
- Machine states: scan, patrol, charge, ranged attack, flee-and-repair at low health.

Definition of done: I stealth in, tear a canister off, shoot it in mid-air, and the blast takes a leg.

Before you start🧰 The toolkit — models, MCP servers, art and 3D

What you lose

Twenty-odd machine designs, each a silhouette, an animation set and a distinct fight
A world rendered in Decima at a vegetation density that is itself a research project
A thirty-hour mystery told largely through audio logs, which is the reason anyone finished it
The armour, weapon and skill economy that keeps the fights escalating for that long

What to steal

Override — flip an enemy's faction id so it fights for you using exactly the AI it was already running

It costs one field, provided your AI asks 'which visible agent is not my faction' rather than 'where is the player'. Then every enemy is also a companion, a distraction and a weapon. Transfers to any game with more than one hostile group: RTS mind control, a steal effect in a card game, tower defence conversion.

ScopeAn evening— build just this, not the game

Single self-contained HTML file, Canvas 2D, no build step. Build a top-down arena with three factions and a conversion ability.

Requirements:
- Every agent has a faction id, and the AI asks 'which visible agent has a different faction id' — never 'where is the player'. That is the whole trick: written against the player specifically, none of this works.
- Two hostile factions plus the player. Twelve agents, chase-and-shoot behaviour, each with health.
- Walk up to an agent and hold E for 1.5 seconds to override it. On success its faction id becomes yours and its colour changes; its behaviour code is untouched. Taking damage during the hold cancels it.
- Overridden agents count against a cap of three. Converting a fourth releases the oldest back to its original faction, mid-fight.
- Add a per-faction kill scoreboard so you can watch a battle you started and are not in.

Definition of done: I override two enemies, hide behind a rock, and the two factions fight each other without me.

Make it different

Not a clone — Horizon Zero Dawn re-themed and cut down to something you can finish. The angle is the important reel: it is what turns a project into a weekend. 24,360 ways to land.

Open Ticket Idle

Horizon Zero Dawn, but an idle version that plays while you are away, set in solo travel. Rendered in modern low-poly diorama.

Themesolo travel

Anglean idle version that plays while you are away

Lookmodern low-poly diorama

Build a browser game called "Open Ticket Idle".

The pitch in one line: a action rpg in the spirit of Horizon Zero Dawn, but an idle version that plays while you are away, set in solo travel.

WHAT THIS IS
Take the SHAPE of Horizon Zero Dawn — its core loop, and whatever makes that loop good — and rebuild it as your own game in a different world at a smaller scope. Use your own names, art and audio, which you want anyway: a reskin of somebody else's game is less interesting than a new one that works the same way.

THE ANGLE — this is the important constraint, honour it above everything else
An idle version that plays while you are away. Offline progress on load, big-number maths from line one, and a prestige reset. The fantasy survives; the input does not.
This is what makes the project finishable. If a decision would push the scope back towards the original's, take the smaller option every time.

THE THEME
Solo travel. Trains, hostels, language barriers and a fixed budget. The journey is the level design.
The theme is not a coat of paint. Let it change what the mechanics mean — a reload, a health pack and a locked door should all be things that make sense in this world and nowhere else.

LOOK
Modern low-poly diorama. Facetted meshes, baked AO, miniature tilt-shift feel, and a colour script of 5–6 base hues max.

REQUIREMENTS
- Runs in a browser with no build step. Canvas 2D unless the angle genuinely requires 3D, in which case three.js.
- Fixed-timestep update loop with interpolated rendering, so it behaves the same at 60Hz and 144Hz.
- Every tuning constant in one CONFIG object at the top, exposed as live sliders in a debug panel. You will find the feel by dragging those, not by prompting.
- All content — levels, entities, balance numbers — in JSON or plain data files, never inline in the logic.
- Audio generated with the Web Audio API rather than asset files.
- Respect prefers-reduced-motion: keep the fades, drop the shake and the parallax.

BUILD ORDER
1. The core loop with placeholder rectangles, at the reduced scope the angle demands. No theme, no art, no audio. Make it fun as rectangles first.
2. The angle's consequences. Cutting to bots, or to turn-based, or to one level changes the design rather than just shrinking it — find out how and rewrite step 1.
3. The theme, as content and data.
4. The look, applied last as a rendering layer over a game that already works.

Start by writing a one-page plan: the core loop, what the angle removes and what that frees you to do properly, and what you are deliberately leaving out. Wait for me to approve it before writing code.

Prior art — read before you build

Half the time one of these already does what you wanted, and the other half it saves you a week of solving a problem someone documented in 1997.

Did you build it?

0Share on X

One count per game. No account — it is tied to a salted hash of your IP, which is not stored in a form anyone can reverse. Every build adds 450 team-years to the counter on the homepage.

Then try these

Or roll something nobody has built yet →

Questions

How hard is Horizon Zero Dawn to rebuild with an AI agent?

Yes — every game is buildable at some scope. The question is how hard, and Horizon Zero Dawn is VERY HARD (4 of 5). You will get a good prototype. The product is what comes after. Component colliders re-driven off the animated bones every tick are the best two hundred lines in this directory, and the machines remain a shooting gallery until an animator makes them move like animals. Reckon on a project to something you can actually play — not to something that matches the 450 team-years Guerrilla Games spent.

What makes Horizon Zero Dawn hard to rebuild?

Component colliders re-driven off the animated bones every tick are the best two hundred lines in this directory, and the machines remain a shooting gallery until an animator makes them move like animals. That is why it sits at VERY HARD rather than a tier either side of it. If you want the idea without the project, the transferable part is override — flip an enemy's faction id so it fights for you using exactly the ai it was already running — an evening of work.

How long does it take to build a Horizon Zero Dawn clone?

Wrong question, and it is worth saying why. Nobody rebuilds Horizon Zero Dawn — the original took Guerrilla Games on the order of 450 team-years, released in 2017 on PS4. What you can do is reach something playable and genuinely yours in about a project, and then keep going for as long as it stays interesting. Any figure that claims otherwise is measuring a prototype and calling it a game.

What do I lose by building my own Horizon Zero Dawn?

Twenty-odd machine designs, each a silhouette, an animation set and a distinct fight. A world rendered in Decima at a vegetation density that is itself a research project. A thirty-hour mystery told largely through audio logs, which is the reason anyone finished it. Those are the parts a prompt will not hand you.

Which AI coding agent should I use to build it?

Any of Claude Code, Codex or Cursor will handle this prompt. Paste it as your first message, let the agent scaffold the project, then iterate on feel — the second, third and tenth prompts are where a game actually gets good. Work in an empty folder or a fresh git branch so you can throw it away cheaply.

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