Summary:
- The upcoming Ninja Gaiden 4 game is expected to have a main story campaign that is around 15-20 hours long.
- In addition to the main story, the game will also feature various side content and activities for players to engage with, such as challenge missions and other optional content.
- The developers have emphasized that Ninja Gaiden 4 will provide a substantial and well-rounded experience for fans of the series, with a focus on delivering a high-quality action-packed adventure.