[In this Gamasutra-exclusive postmortem, the creators of American McGee's Grimm honestly analyze the creation of the Chinese-developed episodic PC adventure series.]

American McGee's Grimm is a casual action-adventure game, consisting of 23 episodes, each designed to offer 30 to 60 minutes of play.

The goal of the game is to convert the shiny, happy versions of some well-known fairy tales into darker versions more closely related to the originals. Players take control of Grimm, an angry, filthy dwarf, and venture into the world of these happy tales to corrupt them with his own dark aura.

Going into production, we knew we had a lot on our hands: we were going to develop the world's first weekly episodic game, and we had exactly one year before the first episodes were scheduled to air.

Since nobody had done a project with these variables, we had to create most of our scheduling and pipelines from scratch, based on the team's instincts and varied experience.

Now, a year and a half after starting development of our prototype, eight episodes of Grimm have been released; sixteen more episodes will be distributed in the next several months.

The game has been very well received: it has become the best-selling game on the GameTap service, and with plans to bring it to other digital distribution platforms, the future looks very bright for Grimm (however much he hates bright things himself!)

What went right

1. The episodic structure

• Production

Grimm is the first game to be released in a weekly episodic format. In fact, we did not see Grimm as one big game; we saw it as one big season of 23 short video games.

Moreover, the first of these 23 episodes would be released halfway through the development schedule, so applying a typical production cycle (where all episodes would be made at the same time, going through prototype, alpha and beta stages at the same time) was out of the question from day one.

Instead, we came up with a schedule of 30-workday "cycles". This was based on the time one level designer needed to take one episode through one production phase. Every episode would go through three main phases (prototype-alpha, alpha-beta, beta-final). After reaching the final stage, an episode would go through a final clean-up stage in the month before its release.

At the peak of our production, we had nine level designers working on nine different episodes, with the art, animation and programming departments dividing up their time to make sure every level got the attention it needed.

Religious adherence to the production plan was all-important: a delay in one episode could very easily delay production for all successive episodes. But, through a well-defined project schedule, a weekly meeting schedule and good overall communication, we managed to pull it off without ever missing our milestones.

Also, with the 30-day work cycles as a base of the planning, everybody always knew when their tasks were due and when new ones would be assigned, adding to the overall efficiency of the team. We essentially developed a production plan that has a lot in common with Scrum, and with good success.

Art pipeline for Grimm. All 3D production was outsourced

• Development

The story-telling in Grimm can be compared to the storytelling in South Park or the Simpsons: every episode is a stand-alone game, and does not require the player to have played previous episodes. Since every episode can be treated as one game rather than one level in a big game, we were able to change up a lot of things every time we started up a new episode.

The biggest change we made was after our prototype episode (based on Little Red Riding Hood) had been delivered to our publisher. Back then, Grimm was able to pick up words from the world (like the word "fire" on top of a campfire, or "rot" from a corpse) and use them as weapons.

This would really make the player feel he was editing the story, we thought. It did not. It felt really unresponsive and just was no fun to play, so we got rid of it and focused on the one thing that did work really well: transforming the environment.

Although we did not make changes as big as that to the gameplay after the actual production kicked off, we kept adding little extras every time we started working on new episodes, effectively making the Grimm experience more and more fun to play.

People playing the game have already noticed these updates -- the public thinks every new episode is better than any of the last -- and now that we know what issues players still have with the game, we can pretty easily adjust the upcoming episodes to be even better!