Changelog

Version: 0.9.19
Date: 2026-11-12
  Bugfixes:
    - Some researches were missing prerequisites, so they could be started before their science packs were available. Cave bulldozer now comes after Excavation and Hardened drill bits (chemical and Mineralogy science), and Bulldozer granite blades and Bulldozer stone vaporizer after Cave bulldozer. Deep ice cooling and Electrolysis come after Aquilo's excavation, Overgrowth soil from fungus after Gleba excavation, Diamond lures after Production science, Shattering quartz ammunition after Military science, Feldspar turret damage after Military and Utility science, and Mineral productivity after Hardened drill bits, Production science, and Utility science. Thanks to the player who reported it.
    - The Electrolytic Cell's recipes (Electrolytic lithium and Electrolytic fluorine) no longer show in the crafting menu; like barreling, they're picked in the cell.
  Graphics:
    - The chain link in a Riser's alt-mode label is green, so it stands out against the pipes.

Version: 0.9.18
Date: 2026-11-12
  Bugfixes:
    - Worms founded underground by expansion sounded the "Enemy expansion base detected" alert with no icon, as they became Brood Mothers or were taken away. Their alert now points at the Brood Mother or nest of their base.

Version: 0.9.17
Date: 2026-11-12
  Bugfixes:
    - The "Enemy expansion base detected" alert for a new horror nest now goes to the players the game itself alerted, so its sound always comes with the alert's icon. Before, the sound could play with no icon when you were elsewhere.

Version: 0.9.16
Date: 2026-11-12
  Features:
    - About one derelict base in four under Fulgora holds the corpse of a settler who didn't make it, named in alt mode with one of the game's backer names, killed by Underground Horrors. It holds a pistol, ammunition, and a start's building supplies, with a few things more (belts, inserters, poles, circuits, and the like). In saves, bases already laid get theirs once.

Version: 0.9.15
Date: 2026-11-12
  Changes:
    - Where a cruise missile lands is charted on the map, as where an artillery shell lands.

Version: 0.9.14
Date: 2026-11-12
  Balancing:
    - Cruise missiles hit far harder than the rockets they're made from. A cruise missile hits twice as hard as an artillery shell, over the same 4 tiles: 3 take down a tier 4 horror nest at evolution 0.49. An explosive cruise missile hits a little lighter, but over 8 tiles. An atomic cruise missile hits like an atomic bomb.
    - Each cruise missile also takes an artillery shell's charge: 8 explosives, and a calcite with Space Age.
    - On the open levels (Nauvis's fourth and Fulgora's), the worms enemies found with a new base underground become a Brood Mother, one to a base. Before, they were taken away, and only the nests there from the start had Brood Mothers.
    - Cruise missiles fly at the nest, worm, or Brood Mother where they were fired, not at a horror running nearby.
  Features:
    - Cruise missile damage research: 5 levels of +20%, on the same packs as Cruise missile range.
  Graphics:
    - The Electrolytic Cell fills its 5x5: it was drawn toward the back, with a strip of bare ground at the front. It now sits in the middle, a little bigger, with a trough of lithium brine along the front and back feeding the pot.

Version: 0.9.13
Date: 2026-11-12
  Bugfixes:
    - The "Enemy expansion base detected" alert for a new horror nest came for nests beyond any radar. Now, as the game's own, only where your radars (or players) see.

Version: 0.9.12
Date: 2026-11-12
  Features:
    - Cruise Missile Turret (Cruise missiles research, after Artillery; Artillery's packs and Mineralogy science): the underground's artillery. A 3x3 launch silo that fires at nests and worms up to 120 tiles away, by itself or with the artillery remote, and can be built underground. Each missile climbs out of the silo, turns toward its target, and flies there level under the cave roof. One missile every 5 seconds; nothing closer than 30 tiles.
    - Cruise missiles, explosive cruise missiles, and atomic cruise missiles: a long range missile of the same kind, a radar, and 2 Technical ceramic. They hit as the rocket, explosive rocket, or atomic bomb they are made from.
    - Technical ceramic: 5 feldspar and a quartz fired into 2 in the Deep Forge.
    - Cruise missile range research: 5 levels of +10% (up to 180 tiles), on the artillery range research's packs and Mineralogy science. Artillery range research doesn't change the Cruise Missile Turret's range.
    - Without Space Age, the long range missiles exist too, unlocked by the Cruise missiles research (the Long range missile turret still needs Space Age).
  Graphics:
    - The Cruise Missile Turret: an armored pod with one silo under red double doors, a quartz sensor, and a small radar dish; the doors open, the missile rises on its flame and pitches over, and the doors close. Icons for the cruise missiles and Technical ceramic.

Version: 0.9.11
Date: 2026-11-12
  Changes:
    - Horror nests on the open levels (Nauvis's fourth and Fulgora's) leave no granite when destroyed: they spread and come back, so it only piled up. Nests on the rock levels still leave it.
  Bugfixes:
    - When enemies founded a nest underground, the "Enemy expansion base detected" alert sounded but showed no entry in the alert bar. It now shows, pointing at the new horror nest.

Version: 0.9.10
Date: 2026-11-12
  Changes:
    - The permafrost under Aquilo is a lighter, frosted grey: Aquilo's snow darkened, in place of its dark dust.
    - Freight Elevators, Risers, and Exhaust Tunnels show how far their dig has come as a percentage of the whole dig's time ("Digging down to Level 2: 37%"), counting the cycle under way, in place of "cycle 2 of 4".

Version: 0.9.9
Date: 2026-11-12
  Graphics:
    - The first level under Aquilo has a floor of permafrost, Aquilo's dark frosted ground, in place of dirt, so it shows that buildings there still need heating. The second level, warm, keeps its dirt. In saves, ground already dug there turns to permafrost, and the rest as it is dug.
  Modding:
    - A rock level's registry entry can give its own `floor_tile`, laid in place of the cave floor.

Version: 0.9.8
Date: 2026-11-12
  Features:
    - Hot Press Furnace (Hot Press Furnace research, after Advanced material processing 2 and Fused quartz; 300 each of red, green, blue, and Mineralogy science): an electric furnace in the steel furnace's 2x2 that smelts as fast as the electric furnace (240 kW), with one module slot, for where space is tight. An upgrade planner turns stone and steel furnaces into it. Made in the Pressure Assembler, underground, from an electric furnace, steel, fused quartz, and feldspar; built anywhere.
  Graphics:
    - The Hot Press Furnace: a banded steel drum in an iron cradle, its fused-quartz window and end seams glowing while a press on top strokes.

Version: 0.9.7
Date: 2026-11-11
  Changes:
    - On Aquilo and Fulgora, Freight Elevators, Risers, and Exhaust Tunnels go through solid ground only: Aquilo's snow, or Fulgora's land, including concrete laid on it. Not through the ocean or anything floating on it: ice platforms, rough or smooth sea ice, or foundation. One placed there from above is handed back with a message, and digging up to such a spot is refused. Elsewhere, water under a shaft's top end still becomes landfill. Ones already built stay.
  Modding:
    - A planet's registry entry can list its `ground` tiles, the only surface tiles its shafts may go through.

Version: 0.9.6
Date: 2026-11-11
  Graphics:
    - Underground Horrors attack visibly: they rear back with their mandibles spread wide, then lunge onto what they bite, the mandibles snapping shut and the scythes slashing down. The old attack barely moved from the game's camera.
  Sounds:
    - A horror's bite is a mandible clack in place of the biter's roar, higher for the small ones and deeper for the huge ones. Frost Horrors keep the spitter's sound for their spit.

Version: 0.9.5
Date: 2026-11-11
  Features:
    - Ground-penetrating radar 4 (Space Age; after Core excavation, 1600 each of red, green, blue, mineralogy, production, and metallurgic science): radars on the third and fourth levels down share one circuit network, as the levels above already could.

Version: 0.9.4
Date: 2026-11-11
  Changes:
    - Freight Elevators, Risers, and Exhaust Tunnels check the far end as soon as they are placed (or told to dig up or down): if a building already stands where they would come out, a placed one is handed back at once, and a choice of direction is refused with a message, instead of finding out only when the dig is done. The check when they break through stays, for anything built there while they dig.

Version: 0.9.3
Date: 2026-11-11
  Changes:
    - The map view's alt-mode arrows over Freight Elevator and Riser ends are the game's full up and down arrows, nearly as big as the building, in place of the small triangle.

Version: 0.9.2
Date: 2026-11-11
  Changes:
    - In alt mode, the map view shows an arrow over each Freight Elevator end and Riser end: down on an upper end, up on a lower one (for a Riser, the way its fluid goes).
  Bugfixes:
    - An Exhaust Tunnel opened its vent above on top of whatever stood there, rails and buildings included. Now it waits, saying something is in the way above, until the spot is clear. Vents already standing on something are taken away once, and open again when the spot is clear.

Version: 0.9.1
Date: 2026-11-11
  Features:
    - Aquilo underground (Space Age): two levels. Aquilo excavation (after Cryogenic science) opens the first, frozen like the surface (buildings need heating) at Aquilo's pressure of 300; Deep Aquilo excavation (after Fusion reactor) opens the second, warm from geothermal heat (nothing freezes) at a pressure of 600, where cryogenic plants, fusion, and quantum processors all work.
    - The first level holds methane clathrate in ore patches, a fuel (12 MJ, as solid fuel) that can also be crushed for ice, and veins of deep ice, which melts into five times the water of surface ice. The brine, fluorine vents, and crude oil above lie below too. The second level has pools of liquid water, more geothermal vents, and cryolite in pockets in the granite.
    - Deep ice cooling: deep ice cools hot fluoroketone back down far faster.
    - Electrolysis: the Electrolytic Cell, built only on the second level under Aquilo, turns lithium brine straight into lithium plates with no holmium or ammonia, and cryolite into fluorine. Its cryolite bath is used up slowly.
    - Frost Horrors live under Aquilo: iced over, as strong as the red horrors, and they spit a freezing stream that hurts and slows, as spitters do.
  Graphics:
    - The Electrolytic Cell: a steel pot of glass cells whose coils glow orange while it works, with gas puffing from its stacks and sparks at the cells. Frost Horrors and their nest, with glowing ice crystals.

Version: 0.9.0
Date: 2026-11-11
  Features:
    - First release. Underground levels, each its own surface: three under Nauvis (Excavation, Deep excavation, Abyssal excavation), a fourth with Space Age (Core excavation, the magma layer), and with Space Age one under Gleba and one under Fulgora (their own excavation research).
    - Freight Elevator: digs a shaft down from the surface or between levels and becomes a pair of ends sharing one 40-slot hold, one electric network, and a circuit readout. Ride it between levels, or look at the other end from anywhere. Removing one leaves an open shaft: build a new elevator on it, fill it with landfill, or drop explosives or an atomic bomb down it to retake the foot below.
    - Underground: ore veins lie under the ore patches above (mined-out ones too), leaner deeper down; pools of spring water; geothermal vents; no sun; pressure rising with depth (1000, 1400, 2000, and 4000), so recipes with pressure conditions follow it.
    - Nauvis's fourth level: an open floor of volcanic ash among big granite columns and lava pools, with coal, calcite, open granite patches, rocks, fumaroles, and stalagmites. At pressure 4000, foundries, big mining drills, and turbo belts can be made there.
    - Gleba underground: rich crude oil fields and patches of Cave fungus, mined by Quarries, which goes into overgrowth soil in place of biter eggs.
    - Fulgora underground: a plain among bedrock columns, with small iron, copper, coal, and stone patches, sparse crude oil, granite patches, and the half-destroyed bases of earlier settlers to reclaim. The first elevator clears the nests within 150 tiles of its foot.
    - Digging machines: Tunnel Boring Machine (a vehicle that tunnels by itself while you ride), Laser Boring Tower (tunnel, expand, or star modes, circuit control), Cave Bulldozer (drive it through rock), Crawler Dock and its Vein Crawler (gathers granite by itself), and Seismic Thumper (flattens cliffs and collapses nests on the surface above, deters new nests, and clears rubble below).
    - Minerals: granite in veins and patches (Hardened drill bits to cut), crushed into quartz and feldspar by the Granite Crusher; with Space Age, pegmatite gives spodumene for lithium.
    - Quarry: a garage whose trucks drive out and mine ore, granite deposits, or Cave fungus in front of it.
    - Production: Deep Forge (fuel-free steel, industrial diamonds, fused quartz, silicon wafers), Pressure Assembler, Mineralogy science pack, Pressed fuel block, alternate recipes for base items, and Pressed granite foundation with Space Age.
    - Geothermal Tap and Wellhouse: steam from geothermal vents, 210 and 420 a second on the first level down, more deeper. Riser: pumps a fluid between levels.
    - Foul air: polluting machines underground stop when their chunk's pollution reaches a limit (map setting). Exhaust Tunnels and elevator shafts let it out above; an Air Gauge reads it.
    - Underground Horrors: the enemy below, grey, orange, and red by level, bigger farther from a level's first elevator. They live in caverns you break into, crush stone walls, and on the open levels breed and spread as biters do, with Brood Mothers that lob their young. On Nauvis's fourth level they are blue, five times as strong, and walk over lava.
    - Defense: shattering quartz and uranium shattering ammunition, Feldspar walls and gate, Feldspar gun turret, horror lures, resonance drones, and with Space Age the Long Range Missile Turret with its own missiles.
    - Research: speed, yield, range, and battery lines; Ground-penetrating radar (radar signals between levels); Tunnel running; infinite Mineral productivity and Feldspar turret damage.
    - Map markers and chat pings are copied between a planet and its levels.
    - Settings: Underground Horrors (startup; off for no enemies below), Horrors climb open shafts (startup, off by default), Peaceful horrors (map), Underground pollution limit (map).
    - Rocket silos and artillery turrets can't be built underground; mech armor can't fly over undug rock.
    - Other mods can add their planets through the "subterrania-planets" mod-data.