Even hardcore gamers want happy endings. And for almost a month, many have gone to war -- social-media war -- to get them.

The much-maligned ending ("weak," "full of plot holes") of "Mass Effect 3," the third game in the popular alien-war trilogy, caused a global storm of gripes on Twitter and Facebook that were organized into a "Retake Mass Effect" campaign.

The grassroots movement gathered gamers to create its own mass effect on developers BioWare, a division of Electronic Arts. With the tagline "Demand a Better Ending," Retake's Facebook page picked up more than 56,000 fans and spawned splinter pages such as Retake Mass Effect Hungary and RetakeMassEffectBrazil. On Twitter, @RetakeME3 has more than 5,600 followers and encourages tweets to include a #RetakeMassEffect hashtag.

It seems to have obtained results. Last week, BioWare founder and CEO Ray Muzkya issued a formal letter that strove to defend the team's creative privilege while admitting it has been "poring over everything." It is working on game content "that will help answer the questions" in April.

Mr. Muzkya called the response "unprecedented" and said that some of the responses had been "incredibly painful."

One blog poster declared Retake "victorious" but added that it was now "time to make sure they get the details right."

Score one for social media? Perhaps. But will the new content satisfy the rabble-rousers? And if it doesn't, what happens next?

"This sort of thing happens all of the time in games -- but usually only with mechanics," said Scott Nichols, an independent gaming writer. "This is the first time I can think of that this has happened with a plot or narrative."

It's a classic crisis-communications dilemma for social media. Marketers need to respond to loyal consumers' concerns, but how far should they go?

At a recent panel about video games as art, Paul Barnett, senior creative director at BioWare Mythic, another one of EA's game developers, was asked about the controversy.

"If computer games are art, than I fully endorse the author of the artwork to have a statement about what they believe should happen," Mr. Barnett said, according to a video posted on the site of tech-news publication The Verge. "Just as J.K. Rowling can end her books and say, "That is the end of Harry Potter.' I don't think she should be forced to make another one," Mr. Barnett said.

Mr. Nichols said that what stood out for him was the response from the Retake blogger about making sure BioWare "gets it right."

"It's the difference between wanting the ending to be changed to be something consistent with the narrative ... to something specific," he said. "It changes their tone from concerned fans to a list of demands."

No matter what it does, BioWare won't please everybody, Mr. Nichols said, adding "I wonder if the "Retake Mass Effect' fans are prepared for that or whether they will burn out their own cause."

Though he wasn't familiar with the "Mass Effect" dustup, Questus co-founder Jeff Rosenblum said he would "counsel any brand from any company that you absolutely have to listen to [critics] -- you can't ignore them." But brands must realize at some point that "customers are customers, and while they're brilliant, the people you've hired and trained are experts, too," he said. "You need to find a way to blend the two."

Some theorists believe that the whole thing was planned -- just smart marketing on BioWare's part. The unresolved ending does seem to set up a perfect future for paid, downloadable content, a strategy EA has been pursuing.

According to DFC Intelligence analyst Jeremy Miller, the good news for the marketer is that while a lesser brand might have been hurt, "Mass Effect" is solid enough to withstand the storm -- and reap the benefits that downloadable-content sales may have down the line.