I played this game through twice on hard and survivor plus, found everything and achieved 100% and can honestly say that it's great! The story is brave and I get that not everyone is going to like it, but I still enjoyed it and felt that it was a great sequel. I agree that it is a must-play game. However, I did like the previous story better. The characters look amazing in Last of Us 2, but aren't as nuanced as they are in the first one and as a result feel a bit flat in terms of character development.
But overall, I enjoyed the gameplay and enemy dynamics more in Last of Us 2 than it's predecessor— there are even parts during enemy encounters where you can enter locations inhabited by zombies and use them to your advantage to take down enemies, but if you aren't careful, zombies or enemies will take you down. These moments in the game were incredibly exciting and fun!
The enemy encounter environments are very large providing some interesting battle outcomes. The suspense and horror elements are great. I would not recommend this game for younger audiences.