- Update the demo — the Oct 20 patch fixed shaders not warming up, which caused effect and scope lag even on high-end PCs. Dev
- Lower your mouse polling rate below ~2000 Hz if turning the camera stutters. Dev
- Turn off in-game V-Sync/G-Sync and FPS limit and set them in your GPU control panel instead (player tip). Dev
Camera stutter: mouse polling rate
The developer explained that turning or looking around could feel like a lag spike, but it was actually an engine issue skipping inputs at polling rates around 2000 Hz and above. A fix was being published at the time. Dev If you still see it, drop your mouse to 1000 Hz in its software and retest.
Effects and scopes lag: shader warm-up
“Several players even on some higher end systems have had lag, specifically with some effects and scopes,” caused by shaders not being properly warmed up. The October 20, 2026 patch fixed it. Dev Let Steam finish updating the demo before testing again.
Random freezing and frame drops
- V-Sync / G-Sync / FPS cap: a player in the official thread recommends turning all of them off in-game and handling them globally in the NVIDIA app or your driver panel. Dev
- Heavy scenes: players report drops with lots of zombies, gore, high ambient light, and stacked fire-rate and lightning effects. Dev Lower effects settings for late rounds.
- Menu stutter: one player noticed hitching only when hovering the left-side buttons in the multiplayer lobby menu, not in-game. Dev
Low-end PCs: potato mode is planned
The developer says the optimization patch was aimed at low-end PCs and that a potato mode is planned, with “quite a big focus” before launch. Dev Check the minimum requirements — Steam lists a GTX 750 Ti-class GPU and 6 GB RAM for Windows. Official
Antivirus flags (Kaspersky “Trojan”)
The developer says the detection is a false positive: the executable is brand new and unsigned, sees heavy traffic and reports information like playtime and gun stats to backend servers, so it gets flagged. A Microsoft manual review was pending. Dev
This applies only to the copy installed through Steam. Never download Mortuus “demo” or “full game” files from other sites. We don’t host any game files.
Linux: stuck on the title screen
- Use the native Linux build, not Wine/Proton. Players
- If it still fails, try Steam Linux Runtime 3 instead of the default runtime in the game’s compatibility settings. Players
- Still stuck? The official Discord is where debugging happens. Players
Steam Deck
Players report the demo running smoothly on Steam Deck, even over hotel Wi-Fi in co-op. Players Mortuus has full controller support. Official
FAQ
Why does Mortuus lag when I turn the camera?
The developer traced one cause to high mouse polling rates (about 2000 Hz and up): an engine issue skipped inputs and felt like lag spikes. A fix was published; lowering polling rate is a quick test.
Is the Mortuus demo a virus? My antivirus flagged it.
The developer says the flag is a false positive: the new, unsigned executable reports gameplay stats to its servers, and Microsoft review was pending. Download only from Steam.
Does Mortuus run on Steam Deck?
Players report the demo runs smoothly on Steam Deck. Valve’s official Deck rating was not shown at the time we checked.
Will Mortuus have a low-end mode?
Yes. The developer says a “potato mode” is planned before launch.
Sources
Labels: Official store page or pinned post · Dev developer statement · Players community report, not confirmed by the developer · Press coverage.
- Dev Steam announcement: "DEMO Optimization Patch" — 2026-10-20
- Dev Developer (Hamuno) replies in "constant freezing and low fps" — 2026-10
- Dev Developer (Hamuno) reply on antivirus false positives — 2026-10
- Players Community thread: Linux title-screen issue — 2026-10-27
- Players Community thread: "Steam Deck Compatible" — 2026-10
- Official Mortuus — Steam store page (app 3680170) — 2026-10-29
Spotted something outdated? Mortuus is still in development; values can change between demo patches and the full release. See how we source.