Monumental is a first-person adventure game set on an alien planet. A group of scientists has vanished while investigating the ruins of an alien civilization. The player's character needs to uncover this mystery through exploration and solving a large number of elaborate puzzles. There are usually based on glyphs and audio segments. The glyphs can be deciphered through translations scattered around and the audio puzzles often have patterns that need to be reproduced. The game offers full exploration in 3D and tools such as a camera, a microphone and a flashlight. Parts of the narrative are revealed through journal entries.