Years ago, I used to play a game for the Nintendo Entertainment System called Star Voyager. The basic premise is simple: you're a pilot of a space fighter, and you need to defeat an armada of aliens who are bent on destroying you and your space station, simply because they are mean.
I wasn't very good at it, but there was a lot to it that kept me coming back to play it again over the years. You could dock at space stations and repair and refuel your spaceship. You could land on the eight planets that actually orbit the center of the galaxy. One of these eight contains an upgraded engine, and one contains upgraded weapons -- both of which feel like necessities when fighting enemies that are very difficult. The euphoric feeling of destroying an alien mothership aside, there were other things to it: the exploration, unknown secrets, nagging questions such as, "How do you escape from a black hole? Can you even do it?" made me keep coming back to try something new. (And yes, apparently you can -- but that isn't what we're discussing today!)
The game itself is notoriously difficult. Even with Game Genie cheats, and your shields up, your ship takes damage from the aliens fairly easily, especially if you have the tendency to fly in predictable patterns. Many people have given up on the game as a relic that was too difficult in the 90's without the manual and without something that gives you a significant edge.
