This really is a fantastic game. The sheer variety of gameplay that is gradually revealed throughout the game keeps the player's interest from beginning to end, never getting boring. The characters are all very well developed and the voice acting is top-notch, adding to the depth of the characters - watch out for Dimitri, he's my favourite character with all his jive talk! You picking up on what I'm throwing down??
Responsive controls, intuitive control system, great music (that sometimes picks up on themes from Sly 2), smooth graphics and some really funny dialogue make this game hard to fault. You don't necessarily have to play the previous instalments in this series to enjoy this game, although there are a few little references that veterans would appreciate. The whole 3D glasses gimmick doesn't work very well, although thankfully you have the option of playing those scenes in normal view.
I can thoroughly recommend this game to those who liked: Ratchet & Clank, Splinter Cell/Metal Gear Solid (the stealth element) and Jak and Daxter to some degree.
Contrary to what one reviewer stated, this isn't necessarily the last in the Sly Cooper franchise - it could be the end, but it is left in such a way that a sequel is most definitely possible.