hyperparticle Open-Sources Craftax-Clearing Agent with Emergent Tactics

hyperparticle has released and open-sourced an AI agent that can beat the 2D survival game Craftax. The full code lives in the craftax baseline of the rekursiv-ai/priml repo, accompanied by a complete unedited recording: the agent defeats the game within 5000 steps. The agent exhibits a variety of emergent autonomous strategies rather than relying on simple scripting.

Confirmed

The author open-sourced the full code for clearing Craftax (the craftax baseline in rekursiv-ai/priml) and posted a complete recording showing the agent finishing in under 5000 steps.
The agent places stone blocks to block incoming projectiles.
The agent places stone blocks to funnel monsters into position (similar to "monster funneling") and strikes preemptively where a monster is about to step, producing kite/chokepoint-style play.
The agent builds docks at the water's edge—where monsters can't follow—as safe footholds, and constructs bridges to avoid combat and survive using terrain.
In the food- and water-less Fire Realm, the agent climbs back up a floor to drink water or hunt bats for supplies before returning to fight, showing long-horizon planning.

Why it matters

These behaviors were not hand-scripted but emerged from the model during play—environment exploitation and long-horizon planning that offer a useful reference for research on generalizable agent strategies.
Open-sourcing the code and full recordings lets other researchers reproduce and verify these emergent behaviors.

2026-10-08 ~ 2026-10-08 · 5 related posts

Primary sources

Open-source agent beats Craftax in 5,000 moves, goes upstairs for water — hyperparticle · 2026-10-08 23:15 (UTC+08:00)
Craftax agent funnels monsters with blocks and pre-fires at their next step — hyperparticle · 2026-10-08 23:15 (UTC+08:00)
Agent builds a pier where monsters can't follow in Craftax run — hyperparticle · 2026-10-08 23:15 (UTC+08:00)

[source] Agent builds a pier where monsters can't follow in Craftax run — hyperparticle · 2026-10-08
Game Agent Blocks Projectiles With Stone and Builds a Pier Monsters Can't Follow — hyperparticle · 2026-10-08
[source] Craftax agent funnels monsters with blocks and pre-fires at their next step — hyperparticle · 2026-10-08
Game Agent Survives the Fire Realm by Climbing Upstairs for Supplies, Then Fighting Back Down — hyperparticle · 2026-10-08
[source] Open-source agent beats Craftax in 5,000 moves, goes upstairs for water — hyperparticle · 2026-10-08