Eco Reactor

Build the loop, balance the system

Eco Reactor is a minimalist ecological simulation built for GMTK Game Jam 2025, based on the theme “Loop.”

Build and stabilize a closed-loop life support system using a variety of devices including solar panels, algae tanks, compost reactors, and more. Each device affects the balance of energy, oxygen, carbon dioxide, water, and biomass in the system.

Each turn, resources naturally increase or decay. Your job is to close the loop before the system collapses.

How it Works

Each turn, natural decay applies:

• Oxygen -1
• Carbon Dioxide +1
• Water -0.2
• Biomass -0.5

Terrain passively contributes:

• Forest tiles: -0.2 CO2 (rounded)
• Water tiles: +0.1 Water

Place devices to transform, consume, or generate resources. Try to keep resource values in their ideal ranges.

Core Features

• A dynamic feedback ecosystem made up of interdependent resources
• 8 unique devices to manipulate the environment
• Procedural terrain with water and forests that affect resource flow

Controls

• Click a device icon on the left toolbar to select it. 
• Click an empty ground tile on the grid to place it.
• Break down modules by hovering over the module and pressing X

Credits

Tools

• Engine: Godot 4.4.1
• Modeling: Blender 4.4.3

Additional Assets

Cog Icon by Lorc

• Licensed under CC BY 3.0
• game-icons.net

Music

"Crystal Cave" by The Cynic Project

• pixelsphere.org

Sound Effects

"Page Turning" by Nicole Marie T

• opengameart.org