That One Level/Video Games/Edutainment Game

Not really That One Level per se, but the desert you must cross to get to California in Oregon Trail II gets on many people's nerves.
- Ditto for that game's river rafting minigame, which is MUCH tougher than the original's and requires a lot of trial-and-error and dexterity with the mouse to pass, especially if you choose to shoot the rapids. And the Sublette Cutoff, which is unavoidable if you're a Greenhorn. If you forgot to bring canteens and/or water kegs, your party WILL die of thirst.
Brain Age 2‍'‍s unskippable connect-the-dot images and acrostics. And when more than one person is using the same game card, drawing a picture of something the game tells you to. All of the above includes getting upstaged by the game proving it's better than you. Because you are facing a professor.
- For people with OCD/impatience, the number memorization game within the trademark Brain Age-checking system. Sure, it's supposed to help your memory, but many just restart their DS when they get to it then re-take the test until they get one without it, because it's too frustrating to complete, but too easy to cheat at by writing the numbers down somewhere.
The crossword puzzle from JumpStart 5th Grade. You're supposed to go through the museum to find the answers, but this tends to take forever (And as many have said, it tends to be pretty well-hidden. Made worse by your parents who could have set a time-limit...making it unwinnable.