12. Afghanistan - Rambo: The Video Game
The Challenge: The final mission of the game takes place in Afghanistan (as per Rambo III), and sees the player mowing down screen after screen of anonymous terrorists of increasing difficulty.
Why It's So Difficult: The rest of the game is such a cakewalk that the final level feels immensely cheap by cranking the difficulty up from about 3 to 11, hurling more enemies at the player than they can ever reasonably take out.
Angry Joe said it best, that the finale of the game has the player ducking and diving as much as they shoot in order to avoid the absurdly accurate fire from the boss-type enemies who show up in huge abundance. Unsurprisingly, a lot of players just didn't even finish the game once they hit this insanely hard brick wall, and frankly, the game's terrible enough that it's not worth bothering with at all.