[In this rare postmortem, originally published in Gamasutra's sister Game Developer magazine, the creators behind acclaimed DS title The World Ends With You at Square Enix and Jupiter describe exactly what went right -- and wrong -- while making the innovative touch-screen title.]

The World Ends With You was our team's first game for the Nintendo DS -- a platform that we felt had limitless possibilities. The three of us who were primarily responsible for the game had previously worked as artists for the Final Fantasy and Kingdom Hearts series, but had never directed a game before.

The game wound up taking two years to develop, which is a considerable amount of time for a portable game, and was a continual trial-and-error process throughout. We feel that the resulting project was eclectic and ambitious, but not different just for the sake of being different.

What Went Right

1. Getting to go wild with original IP and gameplay concepts.

The project began with constant brainstorming and idea-sharing between the three of us. As this was our first game as directors, a healthy dose of paranoia prompted daily brainstorming meetings. These sessions established a strong sense of camaraderie and led for better overall communication, allowing us to constantly meet our deadlines without any serious delays.

From the beginning we were determined to create an original IP -- something that wasn't another Final Fantasy or Kingdom Hearts. This led us to choose the Shibuya district in Tokyo as the game's setting.

At first we thought the Shibuya locale would be a turnoff to overseas players, but the district's uniqueness adds a certain reality and depth that we couldn't have recreated in a fantasy setting, and it lets players identify more with their in-game counterparts, who are fighting for their lives in the "real world."

It turns out we were successful -- even a year after the game's Japanese release, hardcore fans are still organizing tours of the real Shibuya to compare it to the game world.

2. A story created by committee (and free of those pesky RPG plot holes)!

Like all other aspects of development, story development was done by committee. Each director was given his own writing team, which brainstormed over the general story background, plot, and other elements.

Because the over arching story has the player trapped in Shibuya, the story needed an air of mystery about it, so the team was determined to avoid any plot holes.

One contradiction in a story like ours could bring down the house of cards, so the team worked carefully to keep the storyline locked down. The game's designers took part in the writing process as well, ensuring that as many eyes as possible went over the plot, searching for holes and offering input from every conceivable angle.

After the final story was in place, we had our Q/A department go over everything as a final failsafe. To our surprise (and horror), they tracked down several inconsistencies we had managed to miss during our multiple checks.

Their diligence reminded us of how critical it is to view the game from the player's perspective -- and these extensive preliminary story checks are becoming a standard at the company.

3. Implementing a player-controlled risk vs. reward system.

Many agree that the standard JRPG formula of walking around the field and grinding (or running away from monsters that aren't worth your time) can get monotonous and build up player stress.

Another issue on the development side is that tuning combat difficulty takes excessive amounts of time, and there's no guarantee that a designer's ideal difficulty is the same as the player's.

Our solution was the "Active Encounter" system, where players can choose how many enemies they wish to fight and when. This removes mandatory battles with "trash mobs," and allows the player to control the risks and rewards of battle.

Harder battles yield better loot and more experience points. This let players of varying skill levels enjoy the game beginning to end -- at the cost of some game balance.