3D platforming does not get much better.
Most of the levels involve collecting a certain number of gems from killing bugs and returning to the start. However, there a few levels where additional objects and some vehicle levels to vary gameplay. The game takes under a dozen hours to complete but there is at least as much additional gameplay to be had by going back and collecting all the gems and also the egg-shaped orbs and other secrets which are scattered throughout the levels. Collecting these eggs allows you to access mini-games which are parodies of popular movies and are generally something of rhythm games where you push buttons in rapid sequence in order to win. The mini-games aren't exactly a highlight but each is fun for at least as long as it takes to beat it and give you some useful powerups. It is set up so you can compete w/ yourself for high scores on these games but most of the Daxter's replayability will come from further exploration of the main levels.
Visually, the game is wonderful, nearly stunning. Textures are detailed and spaces are immersive and create an atmosphere that sucks you in and makes the PSP feel like a much bigger device. Rather than pushing the cartoony aspect, which is the obvious thing to do in a game centered around a fictional otter/weasel hybrid, and instead goes for a level of detail that evokes a dark sort of surrealism. You can force some slow downs if you play around with the camera buttons while you are, say, bouncing on a trampoline or falling off a cliff but for actually gameplay there are no problems. And, as good, as the graphics are, they are not even the best part of the presentation. The music pulls you in w/ dark orchestral scores w/ just a hint of pop and just enough rhythm to keep it from being too brooding. It matches the visual style perfectly and together, the presentation here is hard to beat.
The story is the only weak point here. The game focuses on Daxter's job as an exterminator and has a kidnapping and world domination plot thrown on top of it haphazardly. Though while the story really adds nothing, the cut scenes are visually engaging and the voice acting is good enough that it really doesn't detract from gameplay--and who really cares anyway? Platformers are the realm of blue hedgehogs saving the universe from evil scientists and plumbers saving princesses from magic turtles. The focus here is on gameplay as it should be.
At the end of the day, this is a visually exciting game that's fun to play. While there are nits to pick, the core gameplay and graphics are almost without flaw and make for a game that is almost impossible to put down until its completed.