The album is the last with the original guitarist Thomas Tofthagen, who left Sahg in order to concentrate solely on his other band Audrey Horne in 2015.

An animated music video was made for "Slip off the Edge of the Universe", directed by Alexander Lillevik.

Delusions of Grandeur marks a turning point towards a more experimental sound and a psychedelic stoner rock genre, radically different from the traditional heavy metal style of the previous three albums of the band.

The lyrics tells the tale of a man who slowly loses grasp of everything he has learned and experienced throughout his life and enters a vast imaginary state where he experiences increasingly severe delusions of grandeur.

The cover art (created by illustrator Robert Høyem) presents an imaginary astronaut on a psychedelic colorful background and geometric shapes.