It's a natural step-up from DR1 in most aspects. The mysteries are harder and more engaging, the grander mystery of the game is relatively more interesting, the setting is more memorable, and the themes and ideas its trying to covey (completely subjective take here) are more compelling.

The cast, well - I agree with what the general consensus says - lower lows and higher highs, and believe me, the positives far outweigh the negatives. In general, a better cast than the first one.

There is still some suspect writing at occasion, but it's an improvement for sure. I can't tell if that's because the writers stepped up their game because the first game's success allowed them more creative freedom or if it's simply because they learned from the first game and decided to wholly embrace the strengths while working on the weaknesses. Could be both. Either way, a very commendable job!

All in all, this is one solid game. The only unfortunate thing is that I wouldn't recommend anyone to start with this game because I think not playing DR1 before it would significantly lower most people's enjoyment of this one. That said, I neither consider that nor say it as a criticism. It just something that is the case for it because it's a sequel much more closely tied to DR1 than video game sequels generally are.