Fantastic addition to the main game. I played this after completing the base game storyline but you could play this before the final credits. It does add background to Jin's character and the events that haunt him in the main story.

Again, the world is a blast to explore. It's fun and rewarding. The environment is beautiful. The storyline on Iki Island was interesting to play. Very cool to explore after a certain point in the story because Jin will have more unique interactions to things around him.

To add on this and the base game, Ghost of Tsushima does a very great job with detail. When you run in mud, your clothes will be muddy. You can leave footprints. Blood splatter, of course, after a fight.

Overall, great experience.