I completed the game with 65% last night. Id say the best boss fights all are in the last 1/3 of the game starting when you get the rope assention engine. I dis onlt one optional tomb the flooded vault. The entire game should have had puzzles like it did maybe.
Great game though. When you complete it you can continue and complete other tasks as well but you are locked into the game once you get to the last campsite just like in far cry3.
The ending is interesting if not over too soon i really i could have fought more oni.