There was a download of Sigma 4.15 on the developer's website when we last checked. We cannot confirm if there is a free download of this software available. Sigma can be installed on 32-bit versions of Windows XP/Vista/7/8/10/11.
The most popular versions among the software users are 4.1, 3.0 and 2.0. The program lies within Games, more precisely Adventure. This free software is a product of Alan Thorn.
We cannot guarantee that the program is safe to download as it will be downloaded from the developer's website. Before launching the program, check it with any free antivirus software. The common filenames for the program's installer are SIGMA.exe, DIRECT.exe, SIGMA PhotoPro3.exe, SIGMA PhotoPro5.exe or Sigma Play.exe etc.
From the developer:
Sigma (18MB) is a mini-adventure. As a traveller who's awoken inside a strange compound, and with nothing but a letter to guide you, you must explore the environments with a hope to discover both your identity and that of a enigmatic creature or organisation known only as Sigma .
You may want to check out more software, such as SIGMA Photo Pro, Sigma Data Center or Sigma Magic, which might be related to Sigma.