Rise of the Tomb Raider is, in my opinion, a great action-adventure game with amazing myths, both main & side stories are captivating and the action sequences, as well as the many other gameplay elements, flow well together.
RotTR is a game that does a great job at keeping you on the main story track if that's what you're there for. I, for one, as a completionist, prefer exploring every corner of a game's world. If you only want to "get it done with", the game flows extremely well when you just stay on the main path. Sometimes, it flows so well that it even tempts me to not go for side objectives...however, if you do like side objectives, there are plenty to discover and they're all fun and, more important, they're meaningful in some way or another; all side objectives (tombs, relics, documents etc) have at least a few words tied to them so that you don't just go and interact with it and then forget it (there are always exceptions (like coin caches, but these are great little puzzles so the fun compensates).
Other things I like:
- the death animations. The sheer brutality of the world around you. You can die in so many ways and it's great to see many different animations depending on how you die. You don't just flop to the ground and see "wasted" cover your screen;
- the amazing puzzle scenarios that come with tombs. Tombs in the TR series are probably some of the most fun side quests I've ever had the pleasure of doing.
- the game world is magnificent and, sometimes, as one would probably expect, a bit tricky to explore. It's a lovely feeling when the game delivers on your expectation of having to go through some hoops for that one random relic.
In conclusion, if you've thought about getting this, think no more. Just do it. You'll have tons of fun.