It’s a bland, mediocre game that’s simply been wrapped up in the aesthetic of a beloved series.
I think that just goes to show that setting and tone play a big part in peoples' enjoyment of games.
That said, I don't think this game will stand the test of time in the same way I don't think Assassin's Creed 1 stands the test of time. It was a really fun first game that showed a ton of promise but also has plenty of flaws and room for improvement. It has since launched a great franchise.
I think the sequels have so much room to grow that I'll likely never need/want to go back to the first one because it'll (hopefully) pale in comparison to the follow-up games.