As the other user said, it was a reboot. One that doubled down on the bad parts of the original and added some new poor ideas on top of it. Stuff like:

• Even worse story - plot of the first game wasn't a masterpiece but it was serviceable. It also focused on a personal story rather than a huge threat like the sequel.
• More combat encounters - something that could've been completely skipped in the original (except for one boss fight, if I recall correctly?) now was forced whether you liked it or not. It also felt worse (to me).
• Locking movement options behind a skill tree - some of the most basic moves from the original game were unavailable for the sake of a worthless progression mechanic.
• Open world didn't flow as well as the linear levels of the first game, it was also poorly divided into districts connected by a few specific routes you couldn't avoid, making it feel even worse.

There's probably more that I forgot at the moment but it was simply a bad sequel which didn't know what made the first game good (in my opinion).

As for how this one is different? We'll see when a public version becomes available. One thing that makes me hopeful is the complete lack of talk about combat on their store page. If they can focus on good movement mechanics and the actual delivery gameplay that in itself will be an improvement over Catalyst.