Alien Invasyndrome Demo Save File Location (Windows)

Why this page exists

Players search for Alien Invasyndrome save file location whenever a run feels suspicious: nest state looked right before quit but rolled back after launch, skill points disappeared mid-run, or a full Security attempt died for mysterious reasons. Locating your save files lets you:

• Verify your Steam install string against the Demo 1.0 hotfix era.
• Back up before risky builds.
• Report reproducible issues with the right paths attached.
• Understand what Steam Cloud does and does not sync.

We will not link unofficial save editors, cracked clients, or piracy mirrors. Those introduce wrong-skill-label and fake-softlock failure modes that show up later as “wiki is wrong” reports. Stick to the official Steam path — see Demo Access, Save & Progress, and Multiplayer & Co-op.

Developer Mozu Field / 百舌鳥, publisher Shady Corner Games, Steam app 4603980, Demo 4830300 (store date 24 July 2026). Full release TBA. Adult 18+; tone stays mechanical. Hub: Controls Hub.

Where the Demo persists (Windows)

Like most Steam games, Alien Invasyndrome Demo writes its persistent state under the Windows user profile. The folder names can change between patches, so this page lists common observed paths and the canonical Steam container you should always check first.

1. Steam userdata container — the canonical location

%SteamInstall%\userdata\<your_steam_id>\4830300\remote
%SteamInstall%\userdata\<your_steam_id>\4830300\local

• <your_steam_id> is the Steam3 / SteamID64 of the account that owns the Demo. If you have multiple Steam accounts on one machine, each profile has its own folder.
• The remote subfolder is the cloud-synced copy; local is whatever was last on the disk.
• Save data is typically saved as a small set of files (*.dat, *.json, or short binary blobs depending on patch). Filenames are not officially documented and can shift.

2. AppData / Roaming (Windows)

Some Demo builds add per-user folders under %APPDATA% for crash logs or convenience caches. These rarely contain the authoritative save, but they’re worth inspecting after a crash:

%APPDATA%\AlienInvasyndrome
%APPDATA%\AlienInvasyndromeDemo
%APPDATA%\MozuField\AlienInvasyndrome

If none of those exist, the build is writing only to the Steam userdata container. Always trust that location first.

3. Local appdata (alternative)

%LOCALAPPDATA%\AlienInvasyndrome
%LOCALAPPDATA%\AlienInvasyndromeDemo

%LOCALAPPDATA% is per-user and not synced. Crash dumps and shader cache often sit here.

4. Documents (rare)

Some older builds exported screenshot folders or quick-saves under Documents. We do not rely on this folder for any persistent state.

How to find your Steam user ID

You can drop your Steam user ID into File Explorer once you have it.

1. Open the Steam client and click your avatar → Account details.
2. The numeric Steam ID is near the top of the page. Copy it.
3. Replace <your_steam_id> in the path above.

If you share your computer with another Steam account, each account is a folder under %SteamInstall%\userdata\. Verify by file size or Modified date.

Read-only steps first (safe)

Before changing anything:

1. Close Steam completely (Steam → Exit).
2. Open File Explorer and paste the Steam userdata path from the where section.
3. Check file timestamps. The file with the most recent Modified date is your active save.
4. Right-click → Properties → read the file size. Compare across sessions.

Always read first, then back up, then change anything.

Safe backup procedure

1. Close Steam.
2. Copy the entire 4830300 folder under %SteamInstall%\userdata\<your_steam_id>\ to a safe location (an external drive or %USERPROFILE%\Desktop\ai-backups\).
3. Rename with a date suffix (4830300_backup_2026-08-24) so later backups do not overwrite each other.
4. Reopen Steam and launch the Demo.

If the Demo now reads stale data, restore the backup folder to its original location while Steam is closed, then relaunch.

Steam Cloud sync behavior

Steam Cloud writes async. A save appears in userdata\<id>\4830300\remote only after:

• The Steam client is online and not in Big Picture mode (occasionally).
• The Demo exited cleanly or auto-saved.
• Steam reconciled its upload queue.

If you suspect a save did not sync, force a Steam Cloud reconciliation:

1. Right-click the Demo in your Steam library → Properties → General → uncheck Keep game saves synchronized with Steam Cloud for Alien Invasyndrome Demo.
2. Click OK.
3. Repeat and re-check the box.

This toggles Cloud off and back on. Steam re-uploads the local state on next launch. Never depend on Cloud alone for sensitive saves — back up locally.

Steam Family Sharing view

Because Steam lists Alien Invasyndrome as single-player (with Family Sharing as a Steam feature, not co-op), save files are tied to the owning account’s userdata folder. A second user borrowing via Family Sharing sees their own attempt, but files do not aggregate. See Multiplayer & Co-op for the broader sharing context.

Save identifier — what your filename contains

Demo save files do not carry an obvious filename pattern today. Within the binary, you can confirm with a hex inspector whether you have the right file:

• First 8 bytes typically contain the magic header for the build.
• Following bytes include the slot index, then serialized state.

We do not publish a magic-byte comparison here. Save-format documentation has historically shipped with the wrong assumptions; treat the binary as opaque and rely on Steam’s folder structure.

What we will not do on this page

• Provide instructions for copying save files between players. That enables unofficial achievement / unlock transfers and risks save corruption across builds.
• Link cracked save editors or trainers. They inject fake skill trees and risk infecting your system.
• Promise that copying a save into another account is supported. Steam’s userdata container is per-account.
• Document how to share files across machines with different Steam IDs. The official path is Steam Cloud on supported builds.

What you can do if your save looks wrong

Symptom	First step	Then
Resume loads an older nest state	Restore local backup from before the bad run	Re-verify against Changelog
Save file size 0 bytes	Steam Cloud may not have synced	Toggles Steam Cloud off / on
Two save files, names unknown	Check Modified date and size in File Explorer	Pick the most recent
Save files missing entirely	Verify install integrity through Steam	System Requirements sanity check
Skill tree looks scrambled	Compare against live Demo	Skill Tree
Pre-boss save corrupted	Restore backup; if no backup, restart run	Save & Progress

Cross-platform notes

The Demo ships for Windows only — see Platforms & APK. On Steam Deck, Windows compatibility runs the same paths inside the SteamOS user profile. Mac and Linux are not first-party targets; do not expect homebrew ports to share these locations.

How to copy a Demo install between machines (legit path)

1. Install Steam on the target machine and sign in.
2. Install the Demo from the official store page — Steam handles userdata rebuild.
3. If you have Steam Cloud enabled, your saves sync once SteamClient is online.
4. If Cloud is off, manually copy the 4830300 folder after closing Steam on the source machine.

We do not link scripts that automate this. Steam’s own tools are the supported channel.

After-locate hygiene

• Do not edit save files. Even one byte shift can break the next load.
• Do not run two copies of the Demo simultaneously. Steam Cloud reconciliation can corrupt state.
• Do not move userdata to a network drive on slow links — local latency will outpace the Demo’s autosave.
• Do not grant write access to userdata for non-admin processes; isolate Steam.

How developers handle saves differently

Save & Progress covers the philosophy: verify against Changelog and trust version strings. Save files are diagnostic only — the real ground truth is your installed Demo version and the active room. This page is purely about finding them, not interpreting them.

Related pages

• Controls Hub
• Save & Progress
• Locale Emulator
• Performance & Settings
• Multiplayer & Co-op
• System Requirements
• Demo Access
• Platforms & APK
• Bugs & Known Issues
• Changelog

Bottom line

The canonical Demo save lives under %SteamInstall%\userdata\<your_steam_id>\4830300\. Other locations are caches. Read first, back up second, never edit. With that hygiene and the Steam Cloud checkbox awareness, save friction reduces to a versioning problem you can solve in Changelog.