Almost like a standalone expansion for the first game. The only differences are a new campaign, almost double the cards and an entire new map. There are also a few new music tracks and the AI is notoriously better.
Opponents will now often require the player to meet certain deck requirements before facing them or add their own special rules which is a nice addition most of the time because in the first entry you had to go out of your way not to run a meta deck. Now at least there's some variation.
The saddest aspect about this title is that its been 21 years since its release at the time of this review, and yet it remains the best singleplayer Pokemon TCG video game in English.