The game is currently in demo release. The demo features 8 levels and one boss. Eventually the game will have (at least) 26 levels and four bosses.

Detailed instructions and help can be found on the download page, but here are a couple of quick links for Windows users:

Dungeons of Darkness Windows executable (needed)
Dungeons of Darkness datafiles (needed)
Manual and walkthrough (optional)
Please note that some information in the manual refers to the full version of the game - you can't find Tell's Ring in this demo, and you won't find any Grim Reapers (be grateful).

Dungeons of Darkness was created using the Allegro game programming library.