Shadow of the Beast (1989)

From Wikipedia Shadow of the Beast is a side-scrolling platform computer game produced by Reflections Interactive and published by Psygnosis in 1989. The original version was released for the Commodore Amiga, but the game has been ported to many other systems. (...) The first game's story is about a man named Aarbron who was kidnapped as a child and corrupted through magic into a monstrous warrior-servant for the evil beast lord Maletoth. The creature's memory of his human life returns when he watches a man being executed, whom he later recognizes as his father. This prompts Aarbron to seek revenge on Maletoth.