This review assumes you are familiar with Roger Zelazny's "Amber" novels. If you're not, don't bother -- the rulebook assumes you've read at least the first five books (the Corwin arc) and is nigh-incomprehensible if you haven't.
An absolute tour de force, one of the most innovative RPGs ever created. Re-creating the ultra-powered Amber universe, where player characters can essentially create planets of worshippers in a matter of minutes and destroy universes on a whim, would be impossible in the standard wargame-based RPG setting. (Witness the Dragonball Z RPG, a valiant attempt at not-quite-as-powerful characters that ends up an algebra textbook.) By using a minimalist rules structure and ranking PCs against each other instead of on a concrete scale, Amber RPG manages the task abstractly.
PCs are built on a certain number of points; they bid these points against one another in auctions to purchase their basic attributes, then go on to use the leftover points to buy powers, strongholds, and artifacts. (Lesser magical items and allies can be created on the fly.) Players have the option of overspending, which will produce a dark character plagued by ill luck, or understpending, which will produce a more likeable character smiled upon by fortune.
The powers and abilities on offer are mostly very flexible. Sorcery is a pain in the butt (but, then, the characters in the novels also whined about its complexity), but the universe-spanning powers Pattern, Logrus, Trump and Shapechanging can all be used as the basis for strong characters. Since most of what a power actually DOES is up to player creativity, duels between characters end up resolved most often not by raw point expenditure but by a combination of planning and tactics.
A wealth of GM information is also provided, including all of the characters from the first five novels (with multiple interpretations of each, yet, including evil interpretations of heroes and neutral views of villains). There are pages and pages of advice on helping players develop great characters, constructing a campaign (including Amber-like universes using Zelazny's core concept but none of his worldbuilding), controlling basically uncontrollable PCs, and adapting the rules to your own tastes.
All in all, this is about everything you could want from an Amber RPG (except, well, any coverage whatsoever of the Merlin books, but that's why they published the Shadow Knight sourcebook).
[5 of 5 Stars!]