Roll your marble to manipulate objects and solve puzzles.
This is the link to download the Oxyd code book, required to play after level 10, not all codes are legible, but the majority are.
Alternate links to the Oxyd Manual: https://www.dropbox.com/s/c99pt71l3156r6j/Oxyd%20Book.pdf?dl=0
And the Oxyd Codes: https://www.dropbox.com/s/rs4lmd6bm6wva3v/OxydCodes.pdf?dl=0
There is also a modern open-source remake that runs natively on OS X, Linux, and Windows: Enigma.Compatibility