STRATA

The deeper you go, the less you can afford to be there
STRATA is an arcade descent through rock that is destroyed cell by cell. You pilot a drilling capsule from a dome on the surface, and everything below the first metre is procedurally generated geology: dirt, clay, stone, shale, granite, basalt, obsidian, ironstone. Each layer is harder than the last, and your drill head either cuts it or it does not.
Depth is the score. Depth is also the bill.
One resource, two jobs
Drilling makes heat. Firing your gun makes heat. It is the same bar. That is the whole game in one sentence: "cut ten more metres" and "survive the next wave" are the same number, split two ways. Waves come for the dome whether you are there or not, and the dome does not defend itself well. Every time you choose to go one seam deeper, you are choosing what the surface loses.
The rock remembers
The world is not a backdrop with a tunnel drawn through it. Every cell you cut stays cut. The shaft you dug on your third run is still your shaft — the mine is a record of your decisions, written into the map. And it fights back. Cave-ins bury the way home. Gas pockets telegraph themselves, then blow a room out of the wall. Water holds you. Lava flows downhill through the tunnels you opened for it. Welded cells refuse the drill you are carrying. Something is following you in the dark, and it is not the thing attacking the dome.
Light is information
Your headlamp narrows as you descend. Ore glows through stone. At depth you do not navigate by looking at the rock — you navigate by looking at what shines through it. Nothing here is an effect for the sake of one; the lighting is how you read the level.
What you keep
A run lasts two or three minutes. What survives it is credits, and credits buy a permanent rig: hull, fuel, cooling, cargo, and five drill heads that open five classes of rock. The full tree runs to fifty thousand credits, and the bottom of the world does not open until you have paid for it. On top of that: run contracts that pay only if you surface, dome specialisations that change what the run is for, relics, fossils, a depth log, and a core at the bottom that is not the end of the game but the start of the second half of it.
Built without a single asset file
There is no art in this game. No sprites, no fonts, no audio files, nothing on disk but code. The font, the sky, the planets, the nebulae, the capsule, every sound — all of it is generated at startup, every time you launch. The download is a few megabytes and the whole thing is one person's source tree.
Features
Fully destructible procedural geology, eight rock classes deep

Heat is shared between mining and defence — the run is one long trade

A dome that is attacked while you are away, and that you have to come back for

Persistent progression: five equipment lines, five drill heads

Run contracts, dome specialisations, relics, fossils, a depth log

Ten achievements — from your first delivered ore to the third core sample

Hazards that telegraph before they kill: cave-ins, gas, water, lava, seismics

Save and resume a descent mid-run

A tutorial that is a mode, not a wall of tooltips

Two languages: English and Russian