So this official visual novel sequel actually takes part just before the "true ending" in the prequel where Okabe has undone everything, back in the beta timeline. Kurisu has been murdered and he is so depressed and traumatised that he refuses to try one last time in reaching Steins Gate where World War III never happens.
Without spoiling too much, Okabe meets Kurisu's former research team Maho and Professor Leskinin and learns about their project "Amadeus" - a system allows the brain to be scanned so that memories can be backed up and restored as an AI. When the team learns Okabe was once Kurisu's friend, they invite him to be part of their research where Kurisu has been "resurrected" with this system and the story picks up from there.
Lots of familiar backgrounds and characters but of course, with new material comes new characters too. As before Steins;gate remains different from other visual novels where choices are disguised as replies to messages. Now it's been updated as a parody to Japan's LINE smartphone app which is similar to Whatsapp but features stickers. Japan has to have their own version of everything after all.
Most of the new characters are well fleshed out but Kagari, an adopted victim of the time travel war (who also has an uncanny resemblance to Kurisu) is probably the weakest new character because she doesn't get much of a role. One or two of the endings were quite bad but the story in-between is really good - both the sci-fi and character development part.
While the first game is known for how well it explains the 11 different time travel hypothesis, here we have a lot about AI and the problems we face creating a human like computer such as how they only follow commands - if you told it to pick up a box and someone wrote "this isn't a box" the AI could pick up the writing and end up not picking up the box.
Seems like just the right time with all the recent debates in the real world media about how AI could turn into Skynet and turn on us too.
On the presentation side, the soundtrack isn't very memorable as the prequel. I still enjoy listening to the prequel's lab theme song and the title screen's piano score but nothing really stands out in this game. No new ring tones either.
Most of the artwork by huke looks amazing despite his signature of dark, gloomy looking colours and heavy lines with a printed texture on them. However, some of the event illustrations where most of the effort is put into in visual novels look a little rushed this time round. Backgrounds based on real locations such as Sunshine Street, Ikebukuro and Akihabara are also very detailed and great to look at.
In the end, Steins;gate 0 feels more of an expansion pack but despite saying that, if you enjoyed the nasty struggles of the prequel then you will enjoy this too. The direction is still amazingly well done which will keep you reading on and the sci-fi part can be quite thought provoking despite the sad scenarios.
And the good news is this game will be localised in English for Steam soon too.