This is the 2nd time that Sephiroth is voiced by someone who has played the role of Superman. He is currently voiced by Tyler Hoechlin, who played Superman in CW's Supergirl series. Sephiroth was previously voiced by George Newbern, who has voiced Superman in the animated series.
This is the first numbered Final Fantasy game where the level cap is not 99 or 100, it is 50. The reason for this is probably because the game ends early in the FF7 story and it wouldn't be correct if the players were too overpowered so early on.
This game was supposed to be remade back in the early 2000's but Square realized that it would be a huge undertaking, so they spent a lot of time working on other projects in the meantime. It wasn't until the end of the Playstation 3's life cycle that Square decided to go ahead with the remake, with the original game makers stating that they were only getting older and were afraid a younger generation will take over and lose the essence of the original. They finally decided to get back together and even got Nobuo to return to compose the soundtrack. The game was in development for over 5 years.
Steve Burton was originally going to reprise his role as Cloud Strife for the remake. However, due to his voice not matching a younger version of the character, he was replaced with Cody Christian. His voice over work on the game can be heard in the PSX 2015 trailer.
Game development studio CyberConnect2 (known for their .hack// and Naruto: Ultimate Ninja franchises) was initially contracted to help develop the game with Square Enix, but in 2017, Square Enix decided to shift production focus internally.