Read the world
Gravity, cavern density, weather, mineral seams, pressure, heat, and liquid hazards change from world to world. A route that works on an icefield can fail in a metal storm.
About the expedition
A long way down. A shared way home.
Project Helios is a mobile-first, browser-based co-op mining game. Pilot a fragile rig across the planets of a solar system, recover construction resources, and build a shared Dyson sphere around the system star.
The expedition
Survey. Survive. Return.
Every run starts at Helios Refinery with a simple brief: open a resource transect, protect the payload, refine it into construction mass, and launch another collector toward the star. What happens next is shaped by the terrain, the crew, and whether you use a field mass driver or return for logistics.
Protect the payload
Induction charge and the survey shell keep the rig moving, but material integrity, resource variety, and depth determine the refining yield. Hard impacts, violent terrain, and pressure can ruin valuable construction feedstock.
Build around the star
Refine recovered resources, upgrade the rig, commit construction mass to the shared Dyson collector, and approve its stellar deployment as a crew. Successful deployments earn persistent cosmetic marks for future rigs.
Candidate worlds
Six planetary profiles. No safe default.
A star-system survey charts three to five destinations. Each biome has its own gravity, crust, weather, cavern pattern, and resource balance, so the crew must choose what kind of danger it can afford.
Aurora Icefield
Low gravity, falling snow, blue-white regolith, and sparse caverns reward patient navigation and long airborne arcs.
Iron Tempest
Heavy gravity and hot red storms make every descent expensive, but dense metal seams give prepared crews a reason to stay.
Hollow Garden
Green mineral blooms and an unusually cavernous crust create fast routes, strange shortcuts, and plenty of empty space to cross.
Glass Dune
Thin air, shifting terrain, unstable pockets, and bright crystal deposits turn a quiet surface into an uncertain dig.
Violet Abyss
Dark crust, rare high-value minerals, deep pressure, and close hostility make this a destination for heavily upgraded rigs.
Tidal Cobalt
Cool terrain, water signals, cobalt veins, and broad caverns create a slow opening with the possibility of a large return.
Crew systems
Built for cooperation, playable solo
A survey can be hosted alone or shared with as many as five other pilots. Positions, recovered cells, placed infrastructure, missions, liquids, and other world changes synchronize through the survey relay. Planet codes make it easy to regroup, while optional access keys let a host keep a survey private.
Working nearby creates crew resonance, which improves recovery. Shared station capabilities lower logistics costs and improve refining for everyone. Rescue missions, tethers, and Orbital Mass Drivers give crews reasons to coordinate routes, while the cylindrical map wraps east to west so a pilot can eventually circle the whole world.
Accounts are optional. Guests can play immediately and keep progress on the current device. A cloud profile adds email-based sign-in and synchronizes compatible progress, cosmetics, campaign records, and sky achievements across devices.
Story mode
The Project Helios Campaign
The story campaign is a separate cooperative path for one to six pilots: six acts, seventeen chapters, and an estimated forty-hour arc. C.L.E.R.A.—Compliance, Legal, Employee Relations, and Apologies—guides the crew through extraction quotas, contradictory records, stranded workers, unusual witnesses, and a corporate mission whose paperwork does not quite match the planets below.
Campaign objectives draw on the same simulation as sandbox play: depth, resource recovery, refining, rescues, anomalies, guardians, station capabilities, biome visits, altitude, and Dyson collector deployments. Progress is recorded at the account level when a cloud profile is in use, so the story can continue after individual rooms close.
Below the surface
A simulation that keeps unfolding
Deep procedural caverns can hold underground water, mercury, or lava. Liquids have different densities, drag, buoyancy, currents, and damage behavior; breached chambers can spill into mined passages, and some mixtures cool into new deposits. Cavern guardians and shared bosses turn certain depths into combat zones.
Signal Anomalies can invert gravity, mask heat, or compress the cargo hold. Thermal signature can trigger seismic surges. Careful extraction preserves payload integrity, while varied resources improve refining yield. Orbital Mass Drivers process and launch cargo underground; Helios Refinery installs rig systems, field instruments, construction pieces, and shared refinery improvements.
Presentation
Designed to run wherever the crew meets
The current build renders its worlds, rigs, particles, materials, and interface procedurally in the browser. Sound effects also have procedural fallbacks, with hooks for authored music and audio. Mobile devices receive touch controls and tuned rendering limits, while desktop browsers support keyboard and connected-controller input.
Ready to descend? The pilot handbook explains the complete run loop, controls, survival meters, upgrades, and crew objectives before your first launch.