Improves on VP1 in a lot of ways. As far as gameplay is concerned, Tri-Ace took VP1's combat, added a third dimension, and considerably refined it. It's way more balanced, it has a lot more depth and is a lot harder to break. In other words, its god-tier.

Compared to VP1, the game is also a lot more linear and the story structure is pretty standard now. Not a bad thing at all, but personally I preferred VP1's structure. The game focuses on the main group way more, but in exchange, einherjar recruitment is now reduced to selecting an option and then reading some optional flavor text.

All in all, it's one of the greatest JRPGs ever made, and I would highly recommend it. Just make sure you play VP1 first, you absolutely need to.