NO, I haven't played any other game from the same series.
YES, I am Greek so I guess this played its part too.
No, I haven't finished it but I have played enough to see its gameplay.
AND YES, this game is really good.

For the experienced players, there is not much to add. Familiar mechanics, a bit improved as usual over last game, in a new setting. For the new ones like me, I was really pleasantly surprised. I am not a big fan of the yearly series but this game is solid fun. Great graphics although a bit heavy for my PC (Intel 2500k, GPU AMD 480, 8GB, average 30-50 FPS all maxed) with many options to lower the aspects you want to sacrifice for more FPS, great sound and music, especially the random voices which are in ancient Greek. Too bad these can be enjoyed only by Greeks and philhellenes because they improve the immersion greatly.

But best of all ingredients is the atmosphere. If you liked the movie "300" you will love this too. The game even begins with you as Leonidas in the tutorial. I was impressed by all the historical information you get as well and I don't mean just the text. Everyday life, clothes, names, myths, it's like all school history books from that era came to life. Great work indeed.

The game really feels and plays like you are in the middle of Ancient Greece, Hellas to be precise, during its glorious but troubling past. If you like our ancient culture, buying and playing it is a great gift to yourselves. If not, well you can still get it in a couple of years, as I read that there will be no Creed game next year, during a sale as it's a great game nevertheless.

Hu-ah!!!

2025 update:
Atlantis DLC has some of the best looking environments I have seen in any game. And believe me, I have seen more than I would like to admit
Still a timeless masterpiece!