Arse Creed III is a good game. Parkour is a point of debate as it gives less control than the previous games, and the combat is almost frustratingly easy making stealth redundant. However, the story is still a high point in the series for me and had me invested to the last minute.
There were some really cool inclusions like naval combat that would become Black Flag, and the homestead that expands on hub ideas from AC2. It's not my favourite AC game and I understand the criticisms levied at it, but I'd play it any day over others.