Metal Earth contains several elements that might be considered anachronistic.
Rock Bands: Several 20th- 21st century style rock bands continuously tour Satan’s Spine. Often they engage in blood feud with one another.
Cigarettes: Mass market pre-rolled cigarettes are commonly available throughout Satan’s spine. Tobacco is produced primarily at S’zan, although a small amount is exported from Rax-Ur as well.
Movies: Accompanying caravans or moving about on their own, independent projectionists travel from settlement to settlement with old style movie projectors and their precious collections of films, mostly westerns, mostly sub-titled in half a dozen forgotten languages, which they display for the edification and entertainment of the latter day masses. Usually projectionists, or their assistants, will stand beside the screen and recite a narrative poem which explains the events in the film. Most of these poems are thousands of years old and passed down through time by the Projectionists Guild.
I'll add to this list as time goes on.
What kind of anachronisms do you have in your game?