I'm sure we can all relate to this situation, where even if the game was considered good, we simply couldn't get into it.
This has happened to me many times but I think the most notable is Assassin's Creed. I've many people I knew praise it and I've always loved action adventure games so I figured I would try getting into the first game... Holy hell, what a boring game that was. Later on, I bought a Wii U and since there weren't many games for it, I picked Assassin's Creed 3 and again, much of the same issues remained, although at least the multiplayer was fun.
Most Ubisoft games tend to be like that, vast open worlds that can only be navigated slowly and lots of collectibles sprinkled everywhere. The only exception to me is Watch Dogs, I enjoyed it.