Campaign was really fun at first but not having Co-Op was a drag at what would have been an amazing sandbox to mess around in with friends. The plot did not grip me and was often predictable, but no one ever came to the franchise for deep plot. You go for the combat - which was very fun for a while but can get repetitive. A lot of what kept me moving was nostalgia for my Halo 1-3 days. Graphics were great, voice acting great, character designs were great.
But the REAL sour note that impacts my rating, the Multiplayer. Multiplayer felt like a husk of the franchise dragged out well before it was ready for it's unceremonious execution. I am glad I was able to play this through Game Pass because I would have felt like this was a waste of money.
Play it for free, play it with friends. The Battle Pass is not worth it and do NOT spend money on this game.