The Blackthorne game was published in 1994 for the Super Nintendo (SNES) and MS-DOS. In 1995 (Sega 32X). In 1996 (Mac) and 2003 for the Gameboy Advance (GBA). The levels throughout the game are not identified by name. Thus, for the purpose of writing the walkthrough I will catalog the levels by their zone tileset (i.e. Mine, Desert) and also by levels.
A level ends when the game progress is saved, for instance.
Blackthorne has 17 levels across four zones.