Side quests are one of the key differences. The side quests in Oddessy are MUCH better -- vastly more interesting, with lots of stages. Side quests in Origins are grind quests, put there solely so you can level. That's really one of the key difference between the games, and where Oddessy wins without question. Skills are pretty cool in both games. I would give the nod to Oddessy here too, because just about all the skills in that game are completely new and original, and some of them (like the "Stealth Master: I mentioned) are wicked cool. And one superb feature of Oddessy is you can reset your skills at any time, any place, for FREE, with no penalties! Pretty damn awesome. Gear, roughly the same, with a slight edge to Oddessy. One thing about Oddessy is you can start figuring out where you can acquire legendary and epic gear (eg. which mercenaries to confront, what Sparta v Athens battles to engage in, etc). Origins, its much more random. Oddessy wins in many more departments -- the scenery is absolutely gorgeous, with a lot more variety too, reflecting Greece's many beaches, forests and snow capped mountains. Origins -- well let's hope you like sand, cuz thats all you're going to get. The cutscenes in Origins are the low point of the game -- they look terrible and shoddy. The cutscenes in Oddessy OTOH are very well done. My only gripe with Oddessy is the loadtimes -- think, Skyrim long. Other than that, given a choice between the two, I'd go with Oddessy in a heartbeat.