Casualties: Unknown Demo Guide: What the Free Build Includes

The Casualties: Unknown demo is not a ten-minute teaser. It is a separate free Steam app with the first five of eleven layers, the full medical simulation and enough crafting to keep a player busy for an evening. The publisher reported 500,000 demo players before launch, which is why the demo's layer routes are already well documented and why the launch build inherits a large, impatient audience.

This guide covers what is in the demo, how long it takes, where the content stops, and what you should learn before spending money on 9 November.

Official source: Casualties: Unknown Demo on Steam ↗

Demo facts

The demo is a separate application, not a beta branch of the main game. Installing it does not install the release build, and finishing it does not unlock anything in the full version. What it does give you is the exact damage model, the exact crafting tree and the first five layer layouts.

How to install it

1. Open the demo store page ↗.
2. Choose Download Demo. Steam may ask you to install the Steam client first.
3. The demo installs as Casualties: Unknown Demo in your library, separate from the main game.
4. Launch it directly. You do not need to own the full game.

The download is small — the store lists 500 MB of storage for the full game, and the demo is smaller still. It runs on Windows 10 64-bit with an Intel Core i3-8130U or better. There is no macOS or Linux build listed.

How long the demo takes

A first playthrough runs about two to four hours if you read the item descriptions and experiment with crafting. A player who already knows the routes can reach the layer 5 loop in roughly ninety minutes.

The demo does not have a final boss or a credits roll. It has a soft ending: you descend through Overgrown Depths, and the next transition loops you back to Deeper Gravel Lands. At that point you can keep playing, keep looting and keep dying, or stop and wait for launch. The loop is deliberate — the game is endless by design, and the demo is a vertical slice of that loop rather than a story chapter.

The five demo layers

Gravel Lands is the tutorial in disguise. Small connected caves, about 15 °C, a Shade crawler population and simple traps. It teaches light management, ledge testing and the first crafts.

Deeper Gravel Lands removes the background light holes and adds water. The main threats are darkness, flooding and Cave ticks. You need a real light source before you commit.

Dried Desert opens into wide sandstone caverns with oil pools and some of the nastiest trap placement in the demo. Turrets, landmines, stalactites and waste pipes appear here. Average temperature is 26.6 °C, so heat and water become a problem.

Wasteland is the radiation layer. It has no enemies at all, which makes it feel safe until a sound cannon, coil or spent fuel rod catches you. The temperature swings from -20 °C to 38 °C. This is the layer that punishes players who ignored insulation.

Overgrown Depths is the jungle. Dense vegetation, edible plants, groundwater, Cave ticks, Sand stalkers, Thornbacks and the Elder Thornback. It is the demo's combat exam. The layer has no turrets or landmines, but the enemies more than compensate.

The full walkthrough covers each layer's route, hazards and recommended gear in detail.

What the demo does not include

• Two of the three launch characters. The demo gives you Experiment, the baseline SAW-01 unit. Milky and Dune appear as NPCs and are marked unreleased for players.
• Six layers. Frozen Chasm, Fungal Pools, Crystalline Hollow, Geothermal Vents, Where We Must Reach and Crimson Ascent are not playable.
• The ending. The demo loops rather than reaching the surface or the final lab.
• Launch balance. Item values, enemy damage and recipe costs can change between the demo and 9 November.

Anything you read about the unreleased layers on this site is labelled as unreleased. The demo cannot confirm those routes, and no guide should pretend otherwise.

Should you finish the demo before launch?

Yes, for three reasons.

First, the medical system is the hardest part of the game, and it is fully present in the demo. Learning to read blood volume, infection risk and fracture pain now means you will not be learning it while the launch crowd is also learning it.

Second, the first five layers are the ones every new player will replay. Knowing where the safe water is in Gravel Lands and which Dried Desert trap patterns are worth a detour is a permanent advantage.

Third, the demo teaches you what the game is not. It is not a fast roguelike; a run can end from a cut you ignored twenty minutes ago. If that sounds tedious rather than tense, the demo will tell you before you spend $22.99.

Demo saves and carry-over

The demo saves locally and through Steam Cloud if Cloud is enabled. Progress does not transfer to the release build. The release starts a new run with a new character, and the demo's loot, skills and layer access stay in the demo.

That is normal for a vertical slice, but it means there is no reason to grind the demo for launch. Play it to learn, not to bank power.

Demo mods and multiplayer

The demo supports the same BepInEx modding path as the main game, and the mods guide explains the loader setup. Most quality-of-life mods work in both builds, but mods that depend on launch-only items or layers will fail.

There is no official multiplayer in the demo. Community co-op experiments exist, and the multiplayer guide separates what actually works from what is still a proof of concept.

What to practise before launch

1. Craft a bag and a canteen without the recipe pinned. You will not always have the materials for a pinned recipe.
2. Treat a bleeding wound in the dark. Find the wound, apply pressure, bandage, then check for infection.
3. Cross Dried Desert without taking a trap hit. Throw something at every suspicious tile.
4. Survive one Overgrown Depths fight without a gun. Melee, terrain and throwables are the intended tools.
5. Climb out from layer 3 with a broken leg. If you can do that, the launch build will not surprise you.

FAQ

Is the demo free forever? It is a permanent free app on Steam as of launch. The developers have not announced a removal date.

Does the demo include the full map? No. It includes five layers out of eleven. The layer 5 exit loops back to layer 2, so there is no hidden sixth layer in the demo.

Can I play the demo after buying the game? Yes, it stays in your library as a separate app. Most players uninstall it after launch.

Does the demo have achievements? No. The Steam API lists no achievements for either the demo or the main game at the time of writing.

Is the demo the same build as the release? No. It is a vertical slice from April 2026. Balance and some item values have changed since.

Sources and further reading

• Steam store page ↗
• Steam demo page ↗
• Official itch.io prototype ↗

Related guides

• Beginner guide: survive the first five layers
• Release date, launch times and price
• Full walkthrough: layer 1 to 5
• Layer order and progression