Demon Sword is an action video game developed by TOSE and published by Taito in 1989 for the Nintendo Entertainment System.

The game starts out with an evil demon ruling over the world and its inhabitants, who live in fear of it. However, a man named Victar, who comes from a small village, has a sword that can destroy the demon. The blade had previously been split up into pieces, though, and Victar must travel through three worlds to get back the three broken pieces in order to restore the sword to defeat the demon.

The game contains three worlds, with two stages in each of them plus a final stage making 7 stages total. In order to regain the pieces of the shattered sword and advance in the game, the player must defeat a boss at the end of every stage. As more pieces of the sword are recovered, the sword itself grows in length and power. The player will also encounter enemies on the way to the boss, which must be defeated with a variety of weapons and magic spells, such as the character's Demon Sword (which he begins the game with), arrow darts, and power beams. The player can also jump over enemies and change direction in midair, as well as land in and run on top of trees. However, the player must be careful when jumping, as there are various traps, such as holes, that the player can land in.