Repetitive and unimaginative gameplay, especially by modern standards, but great story and visual style.
I'll get this out of the way right at the beginning, this game is formulaic in it's gameplay. It is a standard third-person-shoot-em-up where you strafe around the enemy and shoot away. There's bosses and there's platforming, but they're just as boring in of themselves.
Where this game really shines is the other aspects of the design. In particular, the weapons are inventive and fun, and go a long way to helping to fix the problems with the core gameplay. Exploding jack-in-the-boxes, a Jabberwock staff, a Blunderbuss that can kill just about anything, a deck of cards. These weapons are great!
The environments themselves are iconic and distinctive. American McGee imbued this game with an excellent art style, that's as disturbing as it should be. The enemies are properly corrupted versions of the characters from the books and movies, with plenty of imagery to go around.
The story itself is presented quite well. Cheshire Cat in particular provides plenty of great lines, and the exploration into Alice's guilt over her parents is quite interesting, to say the least.
Overall, recommended, just be prepared to slog through some crap to get to the diamond.