AI: THE SOMNIUM FILES - nirvanA Initiative is everything a sequel should be.
It takes the beloved characters of the prequel and puts them in yet another murder mystery while also answering some unresolved questions of the first title.
New characters get introduced and old ones get looked on from a different angle while keeping their unique personality and quirks.
The game itself follows an almost identical approach in gameplay and humour but it tries to introduce the player to more unique ways for each Somnium compared to the prequel. It also spices up the investigation outside of the Somnium from time to time with a kind of murder-scene recreation sequence.
Despite of the plot being a little bit more over-the-top compared to the first title it didn't feel out of place and got incorporated very well into the world while ultimately keeping its own charme. Even more than the prequel it animates you to think and pay attention to solve mysteries inside and outside of the Somnia which keeps the player engaged.

Another thing which is just my personal opinion but the fact that Mizuki is (one of) the protagonist(s) of the sequel makes this even better.

This is a must play for anyone who enjoyed the first title.