Twelve chambers, one way up
The playable game started as a request to make a desktop game on the hardware there is. That hardware is a laptop with Intel HD 5500 graphics, and the bar written down on 9 September was 60 frames a second at 1280 by 720 on it. Drawing only the creatures in the current chamber took the cave from 14 frames a second to 60.
The level is not drawn by hand. It is tunnels.py, the project’s graph of the vents: every node becomes a chamber and every connection a tunnel, in five layers 18 metres apart. Reach names, band depths, stage heights and the bestiary come from the lore, so renaming a reach in the lore renames it on screen. The graph has 12 chambers and 19 tunnels, and 11 of the tunnels spiral up between bands.
Walking, not lifts
Some rules came from watching the recordings. An early version had vertical shafts and climb keys; the note back was that dragons walk between levels and do not ride a lift. Every connection between bands is now a spiral tunnel walked at no more than 32 degrees, placed clear of every chamber and every other tunnel, and ending flush with the floor of the room above. A drake that glided with still legs got a walk driven by the distance it travels, so its feet stay planted.
The first recording, of the 8 September build, is still the reference for the cave’s look: static models, flat panels, one lamp. Six lights with specular highlights, smooth rock with noise colour and a heavy vignette were each tried, and each was taken out.
Rules from the lore
A dragon eats anything at or under 60 per cent of its height at once; larger prey is bitten down and may fight back. Biomass grows it: juvenile at 8, subadult at 30, adult at 60, and growth completes only inside a chamber, so nothing grows stuck in a squeeze. Each band has a gate by stage: the Warrens need a fresh-hatched, the Middens a juvenile, the Undercroft a subadult, daylight an adult. Eat enough of one creature and you take its trait; stand still and watch a living one and you learn half of it. The pit hounds of the Workings are the counter: two or more within six metres is the Baying, which halves your speed. The win is an adult stepping out of the vent mouth.
Five lineages
On 11 September every lineage became playable, each on its own rigged model with its own breath: the Western Drake’s sustained burn, the Fire Wyvern’s bolt, the Eastern Lung’s gale, which harms nothing and sends everything running, the Crystal Wyrmling’s resonance beam and the Thicket Hatchling’s spark puff. The Hatchling stays small, so the squeezes built for the fresh-hatched stay open to it at every stage. On 13 September the Eastern Lung began to fly: its model and clips are coiled, so the game lays its twenty spine bones along the path its head has flown.
The autopilot climbs out as every lineage in about ninety seconds of game time. The climb was tuned towards fifteen to thirty minutes for a person, and no person has timed it. Nobody has played it and given a verdict on controls, clarity or fun; playtesting was deferred on 13 September. The level check passed on 16 September.