This game is a mess. It isn't a good Assassin's Creed game and it fails at being a compelling RPG. A good RPG follows one of two rules for the protagonist, either a blank slate (Skyrim) or a character with a pre-established personality of which all the dialogue options and choices reflect that personality (Witcher 3). AC Odessey blends these two rules to disastrous effect. You have a protagonist, who sort of has a personality, but you can do a bunch of things that contradict that personality, therefore making the character widely unrelatable.
The combat is shallow and the enemies are sponges that soak up damage. The problem is that they scale with your character, so you can never be more than a level or two higher than them. The grind to level up is ridiculous and so many quests are just: go here get that or go here, kill this guy. You end up with an over-reliance on abilities to get through fights.
The world, while pretty to look at, is empty (except for copy-paste forts) and devoid of meaningful interactions that increase immersion. The story rarely makes you feel anything for the characters, and there are some things that are just plain dumb—like seducing the game's main antagonist right in the middle of what's meant to be an impactful moment in the arc.
I love the Assassin's Creed franchise, and before you ask, yes I completed the game to 100% (all of the games in fact). This game, however, should not have been called Assassin's Creed. It brings shame to the franchise. Shame, shame, shame.