Maybe it's why rogue-likes are so popular lately - unpredictable elements and possibly emergent gameplay. Sprinkle a bit of addictive player feedback loops and toss in a pinch of challenging gameplay. Stir three times and you've got yourself a game!
In other news, I am getting a bit hungry.
A Case Study on Portal
Midway through Portal, there's a giant twist. And by most accounts, this is a pretty effective twist. Good game designers ask hard question, so this is the question of the day:
Why is the twist in Portal effective and how do we apply it to other games?
This is a question I've pondered about for quite some time. I used to think that the twist in Portal was only based on narrative, but recently I've noticed that that was only a small part of it. There are plenty of games with twists in their story, but Portal somehow feels more special than that.
Let's take a look at the structure of puzzles in Portal.
Most puzzle games, from Angry Birds to World of Goo to Scribblenauts, have the same general structure.
They are a series of isolated puzzles that have about the same chunk size for each puzzle.
How most puzzle games are structured
However, Portal is structured like this:
How Portal is structured
Portal starts off in a rather traditional puzzle structure. It even has a "level number" for each puzzle. But after the midpoint the concept of isolated "test chambers" melt away. It's just a continuous long environment you travel through with implicit puzzles interlaced along the way.
There are also a lot of differences to the twist besides puzzle structure. A big part of the surprise in Portal is setting up expectations and breaking them. This comes through in the tone, environment, and narration of the game. Most of these come across pretty clear: the first 20 levels are clean perfect testing chambers, and the rest of the game is played - the dingy and dirty spaces behind panel and testing facilities as well as the empty office spaces.
Even the narration style is different. In the first 20 levels, the narration feels very hand-holdy. Something is said at the beginning of the puzzle, at the end of the puzzle, and maybe even while you ride an elevator. Later on, it feels that Glados is actively stalking you.
And this leads me to one hypothesis:
In the player's mind, Portal changes from one genre to another
"Huh. How do I solve this puzzle?"
"HOW DO I GET OUT OF HERE. I HOPE GLADOS CAN'T SEE ME. WHERE DO I GO??"
And maybe that's the key to creating a twist or surprise on the scale of the one in Portal:
Make the first half of the game seem like one genre,
and make the second half seem like another genre.
And when done correctly this could be very powerful. Think about a military shooter game that sudden becomes a stealth game after the first half of the game. Or better yet, a military game shooter that becomes an open world survival game. Ideally, games that cross genres would keep the same gameplay mechanic.
What if a stealth game like Thief suddenly became an assassination game based on revenge? One interesting thing is that to make these changes in gameplay genre will only make sense if you have a powerful change in narrative. This could be an interesting tool.
For example, consider going from "zombie survival horror" to "adventure". The twist might be getting bitten by a zombie and volunteering (or being forced) to leave the human compound try to do the most good possible before your time is up. The gameplay might change from "scavenging and running away from zombies" to "exploring the post-apocolyptic world looking for a cure or another human compound."
And...that's just a random thought I was having. Have a nice day.