There is no permanent "free download" for the general public, but specific legitimate methods exist for obtaining the game at no extra cost:
The game has previously been offered as a free title for PlayStation Plus members (e.g., September 2018). Q.U.B.E: Director’s Cut Free Download
Users who owned the original version of Q.U.B.E. on Steam were granted the Director’s Cut for free. There is no permanent "free download" for the
Legitimate copies are sold through Steam , GOG.com (where it is DRM-free), and various console stores (PS4, Xbox One, Wii U). GOG.com (where it is DRM-free)
Searching for "free download" often leads to unauthorized third-party sites. Downloading from such sources carries security risks and does not support the developers. Key Game Features
The Director’s Cut is the definitive version of the 2011 original, adding several significant updates: