Is Return to Arkham a remaster?

Excuse me, I'm curious about the game "Return to Arkham." Could you please clarify if it's a remastered version of the original games or a completely new game? I've heard rumors that it might be a revamped version with improved graphics and gameplay, but I'm not entirely sure. I'm a big fan of the Arkham series and I'm eager to know if this is a worthwhile purchase for my collection. If it's indeed a remaster, could you elaborate on what specific improvements or new features it brings to the franchise? Thank you for your time.