Shadow Tower is a first-person dungeon crawler from the team that created the King's Field series. Though the two games share a similar style, theme, and look, Shadow Tower is the start of a new series unrelated to King's Field.

The player controls mercenary Ruus Hardy, who, upon visiting the town of Zeptar, finds it razed to the ground. The towns inhabitants have been killed, and their souls claimed by evil spirits lurking below a nearby tower. Ruus heads alone into the underground dungeon to slay the monsters and set the souls free. This journey will take the player through six "worlds" based on nature, including Earth, Fire, Illusion, and Death, and pit them against monsters and bosses alike.

Players control Ruus from a first-person perspective, swinging swords and casting spells accordingly. Players can strafe with the left and right shoulder buttons. Weapons and armor are found around the dungeon and equipped from the status screen. Rings can be found that are imbued with a predetermined set of magic spells. The player can have one ring on each hand, and one spell active for each ring. Players can buy and sell items at shops. Equipment can wear out with repeated use, and must be repaired by a blacksmith or replaced all together.

There are no experience levels in Shadow Tower. Instead, the player builds stats by repeating related actions. Players can find fixed warp and save stones within the world to travel and preserve their progress. There are no maps, either in-game or included with the documentation, so the player must make their own with the help of an in-game compass. The game supports multiplayer only through a limited 2-player battle mode.