Scav Prototype and Casualties Unknown: Same Game Explained

Short answer: Scav Prototype is the original name of Casualties: Unknown. It came out free on itch.io on 31 December 2024 and later took its current name for the Steam release. The itch.io version is still available, stopped at version 5.1, while the Steam game has moved well beyond it. confirmed

scav prototype still gets about 6,640 searches a month (third-party estimate), and people often do not realise it is the same game. Nexus Mods still files it under scavprototype, and one community wiki kept the old name in its address. confirmed

Is Scav Prototype the same as Casualties Unknown?

Yes, same developer, same concept, and an earlier version of the same project. Orsoniks released it on itch.io at the end of 2024, and it had over 300,000 downloads and 24,000 Discord members by April 2026. confirmed The Steam store page then launched under the name Casualties: Unknown.

Search terms still mix the two names, as in “Casualties Unknown (Scav Prototype)”. If a guide uses the older name, assume it describes an older version.

What are the differences between Scav Prototype and Casualties Unknown?

	Scav Prototype on itch.io	Casualties: Unknown demo	Full game
Latest version	V5.1	7.0.1	Full release
Price	Name your own price	Free	22.99 USD
Layers	Up to 5, per community notes	5	10 plus a short 11th
Heart simulation	Older version	Rebuilt in 6.0	Rebuilt
Run settings	Simple	Presets since 7.0	Presets
Achievements	No	No	40
Characters	1	1	3

The big change between them was version 6.0, which rebuilt the heart and blood system, reworked the tutorial and changed “almost everything related to your body”. confirmed Guides from before April 2026 can therefore mislead you on medical advice.

Where can you still download Scav Prototype?

From Orsoniks’s itch.io page, which still offers CasualtiesUnknownV5.1Demo.zip at 286 MB, on a name-your-own-price basis. confirmed The page is marked as a prototype and has been rated 4.9 out of 5 stars by 1,305 people. confirmed That build will not get Steam’s later changes.

Unless you want the older version out of curiosity, play the Steam demo instead. The multiplayer mod and most other mods target the Steam builds, and an older itch download may not work with them.

How did the game develop over time?

The itch.io devlog records a steady stream of updates. confirmed

March 2025: “update 2” added and fixed assorted things.
May 2025: Demo 3 introduced a save and load system, among many other changes.
April 2026: the Steam demo, a new trailer and a rebuilt cardiovascular system.
June 2026: Demo 7.0 with run settings and a pause menu.
November 2026: full release, after “almost 3 years of development”.

Gunsaw is another game by Orsoniks, and Casualties: Unknown shares a setting with it, according to players. Forum players recall finding Scav Prototype after playing Gunsaw on itch.io. reported Players and a community mod use “Gunsaw” to refer to its wider set of species, such as the Voyager. The mod Gunsaw Genetics brings those species into this game. confirmed Players also report that one of the endings foreshadows Gunsaw’s events. reported See the endings and lore page for more, with spoilers marked.

Which name should you use when searching?

You are looking for	Search for
Current guides	Casualties Unknown
Mods	Casualties Unknown or scavprototype on Nexus
The old free build	Scav Prototype itch.io
Fan content	Either

Mods continue to use the Scav Prototype name internally: the mod library is literally on a game page with that address, and modders may refer to either name interchangeably. This confuses a lot of people the first time.

Do Scav Prototype saves transfer to Casualties Unknown?

Nothing we collected shows an official way of transferring saves between itch.io and Steam builds, and the major system rewrites make it unlikely that an old save would behave. Plan on starting fresh. Your knowledge of the game still carries over, except for anything to do with the heart system.

Why did the name change?

We could not find a stated reason in the official posts. A pre-release forum comment describes “Casualties: Unknown” as the intended full title, with Scav Prototype being the early name. unverified Whatever the reason, “Scav Prototype” reads like what it was: a working title for a prototype that grew into a commercial game.

Is Casualties Unknown still free on itch.io?

The older build is, and the Steam demo is free too. The full game is paid, on Steam. Check the price section for details.

Scav Prototype and Casualties Unknown