Well, the complete album sound, stage set, intro choice, cover, photo art and vaguely the lyrical theme for the bulk of the album.
CSiT - time travel, fits
WY - doesn't but works in any production circumstances
SoM - violence in big cities, the future is now moment, fits
HCW - doesn't, uplifting song works in a warm synthy production
Runner - direct metaphor for passage of time as perceived by humans, fits
SIASL - musically its a great fit, lyrics are abstract enough not to derail it
Deja Vu - same as runner, fits
Alex - musically it would be interesting if lyrics wouldn't tie it down to ancient past, which as Brigs said makes it awkward.
So yeah, time and everything about passage of time is too wide of a concept to be called a concept, so it's a theme. When you look at what songwriters did, they made two anthemic live songs, and apart from Alex, all lyrical themes and music reek very much Sci Fi. Guts of this album is SF, such weird and wrong ancient history lyrics, on the main epic, are obviously a letdown.