Sunday, July 24, 2011

Adventures In Level Design: The Long Road of a Failed Design

Over the course of the past several days, I've been working on a series of puzzles for another Portal 2 map. I had what I thought was an exceedingly clever idea for a mechanic to work a puzzle around, so I got to work right away fleshing it out from the ground up.

I began on paper.
The core of the idea was for the player to jump down a deep shaft to gain speed, and land on a 45 degree slope at the bottom. This would have two effects, as I illustrated crudely above. If a portal was placed on the 45 degree slope, the player could shoot out of a flat surface at an angle. Conversely, if repulsion gel was placed on the slope, the player could bounce off of it and into the 90 degree wall at a perfectly straight angle, allowing them to pop out of a portal with a straight trajectory.

I named it the Repulsive Drop. It worked perfectly on paper, but I had my doubts about the physics engine of the game keeping up. So before I built an entire puzzle, I constructed a prototype in a rudimentary room.

The bottom of the Repulsive Drop. The grey areas are where portals should be placed.


The first problem I ran into was that the player would have to be exceedingly accurate in their plunge, requiring them to not only land on the portal, but land on a very specific spot on the portal. If they grazed the edges at all, they wouldn't come out at the desired angle. Discouraged but not defeated, I came up with this solution:

A grate at the top of the plunge makes the initial drop more precise, while leaving room at the bottom for the portal to be placed.
Through some testing and fine tuning, I was able to achieve both desired launch angles from this prototype, so I began construction of a test chamber which implemented it.

I had a puzzle completely designed by that point, so I set out constructing it all in the level editor. The last thing I did was install the Repulsive Drop.

Accuracy was still a problem, so I shrunk the drop point as much as possible.
I gave the work-in-progress level to some friends for play testing. It was important that someone besides me could grasp the logic of the puzzle, and also that other people were able to get the desired results from the Repulsive Drop.

It took them a long time to even figure out what the theoretical solution was, and when they did, they couldn't get the Repulsive Drop to function properly. It turned out that as the designer of the faulty mechanic, I was taking for granted just how tricky it was to get the thing to work properly. No one could make it through the angled portal at the bottom cleanly, and were popping out of it at odd angles.

The nature of Portal puzzles does not require the player to be particularly dexterous or quick with their hands in order to solve a given puzzle. So when they tried to use the Repulsive Drop as intended and it didn't work, they didn't try it a second time, they just assumed the solution was elsewhere. I tried desperately to continue tuning the Repulsive Drop so that there would be no room for error on the player's part, but in the end it was just not possible.

WORK, DARN IT.

Eventually I had to admit to myself that, as much as it pained me to do so, the entire idea needed to be scrapped. Play testers were confounded, and the mechanic was janky in the best of cases. So the past few days of work on this concept have been entirely fruitless, except for the lessons I've learned.


  1. Don't be afraid to let go of bad ideas
  2. Play testers know best
  3. Naming your design ideas makes it that much more painful when they die

With these lessons taken to heart, I move forward to continue work on this map. It's a tough and frustrating thing to give up on what I still believe is fundamentally a clever idea, but it can't be helped. I'll just have to move forward with some better ideas.

Thank you for participating in this Enrichment Center activity

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