If you are asking about the safety or utility of this specific ZIP file found on a third-party site:
: It satisfies a very specific "cleaning" or "completionist" itch. Unlike many survival games, there is no hunger or thirst meter, so you can explore at your own pace. File: Dysmantle.v0.6.8.16.zip ...
Check for "false positives" in the comments of the site you found it on. If you are asking about the safety or
: This is an extremely outdated version. The game has since left Early Access and is currently on version 1.4+ . Using a v0.6 build means you are missing years of content updates, bug fixes, and the ending of the game. : This is an extremely outdated version
If you are looking for a review of the game content corresponding to that version (which is an early-access build from 2021), here is the consensus: