9. XCOM: Enemy Unknown
People rage quit at XCOM for a very, very specific reason: it actually uses statistics, which makes it unexpectedly quite confusing.
Because if you have, say, a 50% chance of hitting a shot, this doesn't mean one in two. It means 50% every time - so if you fire several bullets, the chance of them all hitting decreases.
This is combined with the fact that the game prevents you from save-scumming your way to the best results, making things even more difficult. If you miss a shot in a desperate situation, you can't just cheekily go back and retry your luck, because the exact same rounds will still end up missing.
While you can adapt to this, it's still enough to make anyone who doesn't find out these details more than a little confused, or even angry at the game. Internet forums are rife with people trying to figure out if the game is actively using the statistic element of the game "against" them, with varying degrees of anger.
XCOM doesn't want you to quit, but it's also not going to hold your hand while you are forced to learn maths again through it - and it that means you have to flee it for a time, the game understands.