It is the best game Ubisoft has ever done.
It is the best game Michel Ancel has ever done.
It's a modern sci-fi action adventure that mixes colorful environments and antropomorpic characters with a rather dark atmosphere, takes Zelda gameplay influences and to the fighting adds sneaking, racing, flight and photography.
Characters, storyline, music, technology ('Jade' engine supported three Prince of Persias afterwards), design, gameplay, diversity, graphics, collectables: unsurpassed.
The sequel is eagerly awaited by the fans. BG&E will celebrate its tenth anniversary in November next year, and it's very unlikely that a sequel will be out by that time.
It costs next to nothing today and will give you six to ten hours of great, concentrated fun. I've played it both on PS2 and PC, and I massively prefer the PC version!