8. Navigating Through The Overworld - The Legend Of Zelda (1986)
If you've ever been stumped by a section in a Legend of Zelda game, how do you think gamers felt playing the original? At the time, most games revolved around blasting as many enemies as possible or racing to the goal.
When The Legend of Zelda was released in 1986, it blew gamers' minds. You couldn't win by killing every Octorok you stumbled upon; you had to use your head. If you couldn't surmise where a certain key was, you couldn't complete the game.
To make it harder, it was one of the first mainstream action-adventure games that that didn't have conventional levels. The Legend of Zelda takes place in an overworld, which you must navigate through to locate weapons, artefacts, and dungeons.
Because a lot of areas look similar (or identical), players ended up going round in circles. For a gamer to find a Legend of Zelda guide that showed the entire map must have felt like discovering the Triforce.
Thankfully, you could look at the entire map in future LoZ games to observe where you still needed to explore. How anyone managed to complete the original LoZ without this option is nothing short of a miracle.