Alan Wake ends with a single line and, while we won't ruin it for you, it raises a few more questions than it answers. This isn't a Lost-type situation—the ending was satisfying—but you're left asking yourself what just happened and who was in control of the experience you just had. It is an amazing ending because it gives the player credit, asking him or her to put some thought into what was just shown.

There is a certain power in leaving things up to the player's imagination. During my time with the under-appreciated Metro 2033, I played the game in the original Russian, where not every bit of dialog was given a subtitle. The level of verisimilitude and atmosphere this gave the game was wonderful, however, and the language brought home the very foreign nature of the place to my American ears. I felt like a visitor in a strange, desperate land, and once again the ending of the game drove home the point that my drastic actions were in response to events that I didn't completely understand.

What was going on in Metro 2033? No, seriously. I'd like to know!

Another game that successfully used the art of withholding information from the player was Shadow of the Colossus. You're given something of an idea about what's going on, but the death of each colossus seems to be tragic, not something to be celebrated. The land your character travels is desolate, and the ending leaves the door open to talk not only about what comes next, but what happened before. Would the game have earned its cult status with a more conventional story? It's possible: the gameplay really is enjoyable, but part of the allure of the title is the exploration of that magical land, along with the sense of isolation and wonder the game gives you.

The trick is to give players enough hints and emotional cues that they have a good idea of what's going on, and then take away enough of the detail that their imagination fills in the holes. Done correctly, it can make a good game great.