Nowhere near the first one.
The Combat system is exactly the same , few differences are job classes and that you only control Yuna , Riku , Paine , not many characters like the first one which is a downside to me. No Aeons aslo which is another downside for me.
One other thing I like to point out is that Blitz now sucks , not nearly as fun as in the first one. Theres other mini-games that are fun to play and count for 100% which brings me alternate endings , this game has about 3 alternate endings depending on what you do , some might give you the closer to the series you desire , while others will make you hate the hours you put into the game , luckily youtube has all the endings lol.
Overall keeping most things the same as in the first one and downgrading some stuff makes this game not worth playing. Only reason is to keep up with the story.