The land of Apshai is in turmoil, and the only salvation lies in the magic of the Temple of Apshai. The location of this temple has been lost in time, and many heroes who have sought it have been slain. A legend speaks that only the blood of a hero will be able to reclaim the lost Temple of Apshai, but this "hero" has also perished. However, all hope is not lost, as the wise man Merlis has found the hero's son, whose blood can fulfill the prophecy.
Gateway to Apshai is a top-down action-RPG. As the descendant of a hero, the player starts with basic stats in four areas: Strength, Agility, Luck, and Health, as well as basic equipment, a dagger and leather armor. The player must choose a number between 1 and 99 to generate the dungeon. Once begun, the player must explore the dungeon, hidden until explored and revealed.
The gameplay involves exploring the dungeon, moving in four directions, and using standard abilities mapped to different controls. Players can use various actions, such as fighting with their equipped weapon, casting a LOCATE spell to discover traps, or searching for hidden doors. The player can also pick up items and scrolls that can be used to aid them on their quest. However, many items have only one use.
The Gateway to Apshai is guarded by various creatures, including snakes, swamp rats, bats, and others. These enemies are only visible when they are in the same room as the player and are otherwise hidden. After 6 minutes and 30 seconds has passed, the player is teleported to the next dungeon, where dungeons become progressively more difficult with faster and more vicious enemies.