You cannot open this file alone. You must have every part (Part 1, Part 2, etc.) in the same folder to successfully extract the game.
Below is a draft article suitable for a gaming blog or forum that explains what this specific file is and how to handle it. Poppy.Playtime.Chapter.2-DARKSiDERS.part3.rar
The file is part of a multi-part compressed archive for the pirated "DARKSiDERS" release of Poppy Playtime: Chapter 2 - Fly in a Web . You cannot open this file alone
Most users utilize tools like WinRAR or 7-Zip to right-click on Part 1 and select "Extract Here," which automatically pulls data from all subsequent parts. What to Expect in Chapter 2: Fly in a Web Poppy.Playtime.Chapter.2-DARKSiDERS.part3.rar
Exploring Poppy Playtime: Chapter 2 – Understanding the DARKSiDERS Release