Great show, great game to match.
The Gameplay is very solid. Unlike the past 2D-based Rider games, the game is a full 3D fighter with an automatic but loose target lock for projectiles. There are several modes, including 3 story modes, linear fighter mode, and survival mode. In most modes, you can choose to either fight with a CPU controlled partner, or solo. New characters and modes are unlocked as you clear different modes with certain characters. In battle, most Riders start in masked form, while most worms start in salisworm form. Riders can built up their Cast Off meter to switch to Rider form, allowing you to cast off and use Clock Up and a finisher. Worms can do the same to molt into their new forms. (Fans of the show be aware, there is no Put On function in the game)
Control is probably the only noticable weakpoint of the game. The controller setup is somewhat awkward, and it cannot be altered. After awhile however, it becomes easy to work with. Several moves have the same execution combination, such as Gatack's non-lethal Rider Kick and Double Calibur equip, which can lead to your character's combo string being disrupted.
The audio is mostly directly taken from the show. Yu-ki's "NEXT LEVEL" plays in the opening movie, while Rider Chips' "Full Force" plays when the fighting intensifies. The gameplay music is original to the game, although several tracks are severely lacking. All the actors from the show voice their respective characters with fresh dialogue, and the Zecter sound effects are taken from the show.
Graphics are standard as far as PS2 games go. The armor in the Riders' design will sometimes ghost through the character model when placed in certain positions or movements, although it is nothing too noticable.
While not a revolutionary game, the Kamen Rider Kabuto game is a faithful adaption to the show and a fun game to play. Fans of the show will love it as a Kamen Rider game, and those who have never seen the show can appreciate it as a fighting game.