Immortal, superhuman heirs to the throne of the Real fight amongst themselves, enlisting aid from unreal parallel universes. Uses first-person-narrator-with-amnesia device to preserve some mystery while moving the narrative along and generating sympathy for an asshole-seeking-redemption.
Mildly interesting platonist setting, wherein "there is Shadow and there is Substance" (113); "Of Substance, there is only Amber, the real city, upon the real Earth, which contains everything." Shadow, by contrast, contains "an infinitude of things. Every possibility exists somewhere as a Shadow of the real" (id.). It's Plato's shadows on the cave wall. I should be annoyed by the reactionary implication, but philosophical concepts made manifest as speculative settings are always cool (Abraham lifts from Plato differently for the Long Price
The other noteworthy supernaturalism is transit through artworks--tarot cards, installations, murals, designed all by "an ancient artist to whom space and perspective meant nothing" (114). It's nifty, but not explained.
Amber itself is the "greatest city" in all existence, eternal, &c. (90)--and thus makes its claim next to Palimpsest, Sigil, Tanelorn, Tirion on Tuna, Celaphais, and a hundred others. (Suvudu needs to do a cage match on this, if they haven't already.)
Coolest bits are narrator's returned memories of life on (our) Earth, from 16th to 20th centuries.
Recommended for furry creatures, dark and clawed and fanged, reasonably manlike, and about as intelligent as a freshman in the high school of your choice.