Press Escape for a menu: resume, the controls, favourite or review the game, and the developer's page. Playing alone, the game waits for you.

In co-op, press 1-4 to call out "Wait!", "Go!", "Take it!" or "Run!" to your partner, in the chat.

A card by the tunnel entrance lists the call-outs while you have company.

A Help Wanted notice in the hall: press E there to invite a friend to your museum.

Open your museum to the public from the same notice so anyone can join, or make it friends only again. The host can send a guest home from there too.

Twelve new achievements: for co-op, the shop, rare finds, the survey stand, the Zephyr's glide, the Aegis, today's dig, sliding through a chase, tunnel finds and completing the museum.

Standing at a display cabinet now tells you what it shows and how many visitors that attracts.

Playing with a Steam friend, they can now buy from the museum shop, restore pieces and choose the round's dig too.

In co-op, each player can now take an artifact from its plinth into the tunnel.

A player joining a friend's museum for the first time (or after a day away) now gets the museum's introductions.

A wall integrity gauge in the dig view: the wall's picture cracks, crumbles and trembles as it gets closer to giving, from Stable to Failing.

Play with a friend: when you start the game, choose a public game anyone can join, friends only, or a private game you invite someone into.

Voice chat, using your s&box voice setting (push-to-talk is V).

Your partner's lantern burns teal, so you can tell whose light is whose from the far end of a tunnel, and their name shows over their head when you're close or they're talking.

A friend who joins comes in their own clothes.

Take the hit for the runner: if the boulder catches you while your partner is carrying the piece home, it slows as if it had smashed through a beam.

A co-op leaderboard page on the museum's board for museums finished together.

The museum says when a friend joins or leaves, and welcomes you when you join someone else's.

A microphone mark shows while your voice is going out.

A museum shop now stands by the tunnel arch, and opens once you have your first exhibit. Spend the kudos your visitors pay on upgrades for the museum, your plinths and yourself.

Five boosts, each for one round: Slider soles, Fleet foot, Steady hands, Head start and Lucky pockets. They cost more the deeper the museum digs.

The closing bell is now bought at the shop, and once bought it stays in every museum you open.

The boosts you bought are shown in the corner of the screen during the round, and light up when they help you. Slides kick up dust, running leaves wisps at your ankles, extra taps glint, and lucky finds flash gold as you pocket them.

Plinth enhancements: give a piece's plinth a finer stand, then gallery lighting, then a stand made for it, so it draws more visitors. The Seer's Eye and the Rosewood Casket have theirs; more are coming.

Rare finds: nine unique antiquities hide in the mounds, given away by a rainbow glint. Bring them home to keep, along with your first pottery shard, bead and coin.

Display cabinets: buy up to four and your kept finds fill them on their own, behind the plinths, for more visitors.

From your third dig on, small finds hang in loose rock on the tunnel ceiling, out of reach on the way out. When the wall gives they shake loose onto the floor, landing just past a pendulum or on a collapsing floor. Run through one on the way home and it flies into your belt in a burst of sparks; it sells with the rest of your finds if you make it back. The boulder crushes any you leave behind.

From your third dig on, the tunnel is roped off until you choose your route. A survey stand by the arch offers two ways down to the same artifact, each with its own ground, and the rougher one pays 50% more kudos if you bring the artifact home. Bring home the Surveyor's Scarab and it maps both routes, showing what lies where before you choose. Press E at the stand, then hold 1 or 2 to take a route; the rope comes down for the one you pick.

From your second dig on, each dig can come with its own conditions: the artifact is buried off-centre, rich ground with more to find, a quiet tunnel with fewer hazards and pits, or a cracked wall that collapses sooner but pays 50% more kudos from visitors if you bring the artifact home. The round card explains it in chalk before you set off, the same mark is chalked on the stone of the tunnel arch until the dig is done (walk up to it for a reminder of what it means), and it sits in the corner while you dig.

Once you have the Seer's Eye, it lights up the next exhibit's place on the collection board in its own gold. The place stays lit until you bring that piece home, then the light moves on to the next.

An opening that says what the museum is for before you take control.

A second sequence after your first exhibit: the crowd it drew and why, that the artifacts that provide passive abilities can go back into the tunnel with you, and the bells purpose.

Tap E to step through either sequence; hold E to skip it.

An exclamation mark by the dig cursor when it is over the artifact itself.

A prompt pointing up the tunnel to the digging site once the pit is behind you.

The dig draws rings on the dirt showing exactly what the next tap will take away, how far it spreads and how deep it bites. Handfuls of dirt stack up three rings, stone gives one tight one, and ground with nothing left to give barely draws at all.

On your first dig, a brass surveyor's mark rings the spot worth starting at. It goes as soon as the piece shows, and you never see it again once you have taken one.

- The first time a dig wall gives way, it holds a moment longer and tells you what is happening and what to do about it. You only ever see it once, and it never costs you any ground.

- A collection board beside the tunnel entrance, in view the moment you spawn: twelve carved places, one for every piece the museum can hold, in the order you will dig them up. Each holds a carved symbol of its piece, cold until that piece is secured and warm once it is - on its plinth or out with you as a tool, both count.

- The four pieces that can be carried back down as tools carry a mark of their own, so you can see there is something more to them before you have found one.

- Museum leaderboards on a brass board in the hall, opposite the bell. Press E to read the whole thing: the top fifty, and your own place wherever it falls, scrolled with the mouse wheel.

- A finished museum now lands on a board. Your score is the visitors your museum drew divided by the rounds it took, so care pays and a lost round costs - it never rewards rushing.

- Today's dig: one seed a day, so everybody walks the same twelve corridors that day, with its own board for the day.

- Your best run of the day is the one that counts, so you can go again as often as you like.

- Press Tab while reading the board to move between all time and today's dig.

- Ring the bell and you are asked what you want, with what each choice costs: close the museum, or run today's dig. Hold the key rather than tapping it, and a museum is never closed without a second ask.

- Kudos: your museum now earns kudos every round from the visitors it draws. The end-of-round screen shows them walking in and the kudos coming out as coins, and back in the hall you watch and hear them drop into the collection box by the tunnel entrance.

- Restoration: stand at a damaged exhibit and press R to spend kudos on repairing it. The prompt tells you its condition, what the repair brings it to and what it costs. A repaired piece draws more visitors from the end of that round, but it can only be brought to 75% - a perfect piece has to be dug out clean. A small gold coin appears over any exhibit you currently have the kudos to repair.

- Small finds in the dirt: a pottery shard near every exhibit, and glazed beads and old coins buried deeper. Dig one out and it goes in your pocket.

- Once the exhibit is dug clear, anything still buried glints in its own colour - terracotta, teal, gold. The rarer it is, the deeper it lies.

- A pocket in the corner of the dig view shows what this mound holds and what you have found.

- Get home alive and your pockets sell for kudos: on the end-of-round screen each find goes into the museum and comes out as coins. Get caught and you lose them.

- Taking the exhibit no longer brings the wall down at once. The wall holds a few seconds longer - longer the fewer taps you used - and every tap in that time is free. Dig fast for what is glinting, then run. Stepping back sets the boulder off straight away, and so does digging out the last find.

- Play as your own s&box avatar. A mannequin stands to the right of the tunnel entrance wearing your clothes. Press E to swap with it, and E again to put the caretaker's uniform back on. Your choice is remembered.

Improved:

- Crouching and sliding are now taught. As you enter the third round's tunnel, and the first few times you run up to something you have to get under, the game shows that C or Ctrl crouches and that holding it at a run slides.

- The tunnel now reminds you that holding right mouse looks around while you run out. It shows the first couple of times and stops once you have used it.

- The opening hint in the hall now shows the plain mouse for looking around.

- The museum has visitors. A crowd gathers behind velvet ropes on both sides of the hall, murmuring, and grows with your collection's fame, up to 38 people in nine looks. Soft dust drifts over the exhibits and the hall fades into darkness at its edges.

- Twelve one-of-a-kind artifacts to dig for, given up in a set order from the forgiving pieces to the ones that punish a careless swing: the Rosewood Casket, the Seer's Eye, the Sun Urn, the Surveyor's Scarab, the Coiled Jade Dragon, the Zephyr, the Celestial Egg, the Warden's Aegis, the Gilded Ammonite, the Regent's Crown, the Laughing King's Mask and the Oracle's Knot. Every piece draws its own crowd, the deepest showpieces most of all, and every piece shows its knocks: chip it in the dig and it comes home visibly cracked.

- The Warden's Aegis: wear it on your back and, once per round, it saves you from the boulder, shoving you clear in a burst of dust and knocking the boulder back. Its amber heart glows while the save is ready.

- The Surveyor's Scarab: carry it and it senses what is coming. Its antennae lift as the next danger nears, a mark over your head names it with a pictogram and fills as you close, and the piece on your back lights along its shell. It is the only thing that warns you about bad ground.

- Combination traps, from your third exhibit onward, one new arrangement with each exhibit after that, each set tight so the second trap lands where the first puts you down: a pendulum over a pit, a pendulum where the collapsing floor leaves you, two pendulums swinging out of step, rocks on a pit's take-off, a beam to crouch under the moment you land a jump, a rockfall beside a breakable floor whose rubble half blocks the way out of the pit, a pendulum swinging across a stone door's opening, a breakable floor right past a door, and a jump beam with a pit a stride after it.

- The fallen beam: a stone beam across the tunnel at chest height. You cannot run through it or jump it, so crouch under it. On the run home the boulder smashes through and barely breaks stride.

- The sliding stone door: carved slabs in a stone frame. Tap E beside a slab to slide it into its wall on the way in. On the run home tap E to pull a slab back across behind you. The boulder has to smash through, and shutting it buys you a moment.

- Bad ground, deep in the tunnels: straight stretches that have come down before, with broken props, spilled rock and someone's dropped lantern. Old beams lie flat along the wall in their posts and swing out across your path as you reach them. Duck the high ones, jump the low ones. The post's height is your only warning, and not every post still has a beam in it. Shallower rock gets a gentler version first, growing from one beam to three as your collection grows.

- Slide: press crouch while running to drop into a slide that carries your speed. You steer less while sliding, dust and grit kick up behind you, and a piece you are carrying goes out in your leading hand. C crouches as well as Ctrl.

- The rock changes as you go deeper. Bring three exhibits home and the tunnel turns to grey limestone under cooler light. Deeper still it is basalt: near-black, tight-fractured, with sparse teal mineral in the walls and the hazard lights turning cold against your warm lantern.

- Hazards on the way out now cost you. Take a hit before the dig and one of your lantern's four panes breaks, the flame gutters, and you walk on by less light. Something up the corridor answers every hit, and when you arrive the dig face shows the knocks you took: the wall gives up sooner.

- At the dig you hold your lantern up and it follows where you are digging.

- Your museum is saved between sessions. Close the game and come back to the same exhibits, scars, visitor count and round. Quitting during a round counts it as lost, along with anything you carried out.

- The closing bell beside the tunnel arch ends a run: ring it, ring it again, and the bell tolls, the hall hears what the run drew, the door shuts, and a new museum opens.

- An artifact you fail to bring home is not lost. The dig offers the same piece again next round in a fresh tunnel, at the condition you left it in, and the boulder that caught you takes its own share out of it. It never comes back worse than poor.

- The run ends when the last plinth is filled, not after a fixed twelve rounds, so losing a round costs you a round instead of the finish.

- The end-of-round summary finishes with what is ahead: the piece you dropped and whether it went down worse, the plinths still empty, and any tool waiting on its plinth.

- Eight achievements: your first find, a piece on display, one brought home pristine, a clean run home, one more round, a tool carried out, five plinths filled, and a crowd of 1,000.

- Hold the right mouse button on the way out to swing the camera around you. It settles back behind you when you let go.

- Sounds: gravel footsteps and a landing crunch in the tunnel, the pendulum's whoosh, a slab crumbling under your foot, harder rock impacts, the crowd's murmur, a scrape that travels with your slide, and a real door closing on the museum.

- The boulder now smashes through the dig wall in a thick cloud of dust and flying rock, and the broken mouth stays behind with rubble on the floor.

A second before each rock falls, a pale ring appears on the floor where it will land, with a puff of dust and a rattle from that spot. You no longer have to look up at the ceiling, or memorise the lanes, to get out of the way.

- A landing mark: while you are in the air, a dark disc on the ground shows exactly where your feet will come down. It sits on the lip as you jump a pit and drops out of sight while you are over the hole, so you can tell whether you will make it.

- The stretch of tunnel under a rockfall now has small stones lying on it and the ground is dented and broken where the rocks come down, so you can tell rocks fall there before the first one does.

- The floor under a pendulum is scraped where the stone swings, as wide as the stone itself, so the swing shows its history to the player before it moves.

- Your first dig is a smaller mound with the piece near the middle, and the old dig in it opens onto the pale seam. A line under the dig view tells you the seam means the artifact is close. Digs grow back to full size over your first few finds.

- Come home carrying a piece and the plinth it belongs on lights up, with a line saying to display it there.

- Step out of the dig and a prompt offers E to go straight back in. No need to walk away and come back.

- Dig near the buried piece and the chips sound and look warmer the closer you get. Dig into the core and it cracks and shakes, and the danger cue joins as the wall weakens.

- There is bedrock under every mound now. Reach it and a tap gives a dull knock and a cold spark instead of dirt: nothing here, dig elsewhere.

- Run a dig long and you can hear the boulder waking up behind the wall, well before it comes through.

- The Seer's Eye, a jade eye in a bronze armillary, granting reveal when taken in.

- The Zephyr Idol, a winged idol who grants glides when taken in, and whose wings open when you leave the ground carrying it.

- Two more finds for the collection: the Surveyor's Scarab and the Gilded Sun Urn. They grant no power, but a well-kept one draws a good crowd.

- A round ledger. Between rounds the museum records what just happened: the piece you brought back and the condition it is in, what damaged it and by how much, anything you lost, and the visitors it drew. Read it at your own pace and press Continue when you are ready.

- The boulder carries a light ahead of it that turns orange and then red as it closes on you, and dies away as it reaches the doorway.

- The tunnel has dust and stone in it now: the dig wall cracks and sheds as it gives, the boulder comes through in a burst of dust and chips, kicks up dust as it rolls, throws a ring of it as it slams into the doorway, and the crumble raises a cloud over the rubble. The pendulum sheds dust as it sweeps, and the rockfall breathes dust from the ceiling before it drops.

- The hall has its lights: floor spotlights beside the entrance on the title, uplights along the walls, and a small lamp in front of every plinth label.

- A floor beneath the world. If you ever end up under the level you are put back in the hall instead of falling forever.

- A way out of a wedge. Push against something with nowhere to go, or hang in mid-air, and you now work your way free instead of losing the run to it.