Obviously a technological improvement over the first game
Visually the game is much more advanced. The gameplay is much faster and smoother now, resembling a more modern fighting game, and the characters feel more individualized now, with different basic attacks and animations.
However, AI reaction times here are ridiculous. Opponents are somehow able to block after you already started the attack. This makes some of the latter fights in the arcade mode extremely punishing, almost to an impossible degree. It becomes very clear in the final fight, which is underwater, making every movement slower, and allowing to actually see how cheap the AI is. Plus I'm not a big fan of how few attacks from a standing position can target a crouching opponent. You pretty much have to keep playing crouching games with them, guessing whether to do a higher or lower attack, and the same with blocking. Combine that with the fact that an opponent can transition from a sprint to a block instantly. It means that, whenever they're charging you, it's almost up to chance whether you'll be able to avoid getting hit, let alone hitting them.
And after beating the arcade mode, again, there's no story and not much else to do here. There's a ranking match mode, which I'm not interested in.