9. Final Fantasy XIII
Though it's entirely reasonable for massive RPGs to serve up sizeable tutorials right out of the gate, Final Fantasy XIII took this to hair-pulling extremes with an agonisingly comprehensive and drawn-out series of tutorial lasting more than five of its 40-50 hours. That's about 10% of the entire damn game.
It's all well and good coming up with nuanced gameplay mechanics that require the player to pay attention and think about what they're doing, but it needs to be fun and delivered in a way that keeps the player both engaged and excited. Of FFXIII's many failures, this was its worst.
Making matters worse, however, was that even when you'd dispensed with the main tutorials, the game holds your hand along a corridor for another 20-or-so hours, while occasionally fielding out more tutorials, before finally allowing you to explore the open world.
This drip-feeding of information was presumably intended to break up the tedium, yet ironically made a solid half of the game feel like a soulless chore. Sometimes less is more.