MarsRover Mine, Build, Breathe

You land on Mars with a bad drill, a small battery and one job: make the air breathable.

The atmosphere starts at 0.0% oxygen. The run ends - as a win - the moment it reaches 21%, which is Earth's. That is the only ending there is. Everything else you do on this planet is in service of that one number.

MINE THE SURFACE

Tap to drive, tap a deposit to cut it. There is no auto-collect and nothing is picked up by being driven over, so what comes home is what you chose to take. Seven metals from common iron to exotic iridium, two rare-earth patches that have to be tapped on their own outline, and radioactive shards that will not ride in your boxes at all.

Price and scarcity run opposite ways, and the rare species are weighted towards the outer map - so earning well means driving further than is comfortable on the battery you own.

BUILD THE ATMOSPHERE

Four oxygen plants, each dragged out of a box onto the exact ground it belongs on. Bore for water ice and cap the strike with a gasifier. Find an oxygen pocket and stand a dispenser on it. Grow mushrooms on radioactive shards. The ladder runs the useful way round: the harder a plant is to site, the better it pays for what it cost.

None of them is bought with money. Like the rover's own parts, they are built out of what you dug up, at a workbench, so what a machine really costs is how far out you had to drive to find its ingredients.

CLEAR THE RADIATION

Roughly a sixth of the surface is contaminated ground that takes 2 hull a second out of 50 - and the armour shelf does not help, because the counter is a lead shield. Crossing the widest zone very nearly kills you.

But a zone is not permanent. Plant a mushroom and two minutes later its mycelium takes the contamination out of a wide patch round it, for good. Enough of them and the zone is gone from the map - the stain, the warning stakes and the hull cost with it. It is the one thing in the game that unmakes a hazard.

UPGRADE EVERYTHING

Four shelves - battery, engine, drill and protection - five parts each, spanning up to ten times what you land with. The landing rover is meant to feel inadequate. Bits wear out and get re-tipped, hulls get beaten back into shape, and every one of those jobs is paid in ore.

HAUL IT HOME

Two trailers you can hitch nose to tail: a shielded hopper that is the only thing a radioactive shard will ride in, and a derrick that bores prospect holes. Every trailer on the train costs you top speed, and in a radiation zone speed is hull.

LOSE THE ROVER, NOT THE RUN

A flat battery or a broken hull costs you the machine, not the expedition. A new one lands free at the pad - you lose the hold and the parts you built, and any trailer it was pulling is left standing where it died for you to drive back out to. Your credits, contracts, plants, solar farm and everything in the store room belong to the run.

ALSO IN THE BOX

• Thirteen optional contracts, all of them watching from the moment you land - there is nothing to sign up for
• Dynamite, for boulders that are in the way and for mistakes you will make once
• A solar farm you lay out on a lattice, because charge is generated, never bought
• Procedurally generated maps from a seed you can type in, so a map you liked can be played again
• One expedition, saved as you play - close the app mid-drive and CONTINUE picks it up parked where you left it

WHAT IT DOESN'T DO

• No in-app purchases. Nothing in the game is for sale.
• No multiplayer, no analytics, no accounts.
• Plays fully offline. The only thing that ever touches the network is an optional rewarded video - one that limps a dead rover back onto its wheels, one that ships in a unit of ore. With no connection those buttons simply go dead and the whole game still finishes.
• No energy timers and nothing that waits on a clock you can pay to skip.

Every visual in the world is drawn procedurally. Bring a battery.