A sidestep rather than the step backwards Sigma 2 is to NG2. Most changes are admissible. Not necessary but not unwelcome either. Some arenas are different, there's some extra fiend challenges, some areas & encounters have new formations & enemies... A few puzzles get simplified and a mini boss or two is added or reworked. But Rachel missions honestly suck, it's not even half has fun as Ryu with the war hammer, only upside is some aren't too long. Mission mode is also switched up a bit.
Given that NGB is a great game to replay on higher difficulties to see new types of enemies, attacks, changes in exploration... it's not the worst to play like a remixed version of it. And includes some nice additions like dual katanas but overall so much is passable or unwanted that it ends up not as good. Worse, while it's presented nowadays as the definitive edition of NG, it doesn't fix some problems NGB had but instead creates new ones of its own.
But it still has the core gameplay and feels at least like 75% of the main game; it's not a terrible thing to start with or even try out despite having played black.
Given that NGB is a great game to replay on higher difficulties to see new types of enemies, attacks, changes in exploration... it's not the worst to play like a remixed version of it. And includes some nice additions like dual katanas but overall so much is passable or unwanted that it ends up not as good. Worse, while it's presented nowadays as the definitive edition of NG, it doesn't fix some problems NGB had but instead creates new ones of its own.
But it still has the core gameplay and feels at least like 75% of the main game; it's not a terrible thing to start with or even try out despite having played black.