"We had to get in frame by frame and turn it into 3-D, which was a long, laborious task," Chu said, "but ultimately I think it really helps our movie."
But will it be enough to bring fans into theaters?
"Unfortunately, movies somehow get a stigma by moving (dates)," said producer Lorenzo di Bonaventura. "There's also some people who go, 'Oh, was that movie not good enough? Is that why you guys pushed it?' So you've got to work your way through some of that as well."
The producer had also hoped to make the film in 3-D originally, "but we didn't have time to do it properly," he said.
Chu had two 3-D movies to his credit ("Step Up 3D" and the 2011 documentary "Justin Bieber: Never Say Never"), and expected to approach the G.I. Joe sequel three-dimensionally, too. Even though it was shot in 2-D, the director said he brought a 3-D sensibility to filming.
"Depth is always part of my language now, only because I had to do it for the last four years. So every scene, even though it wasn't in 3-D, depth was a part of the frame," he said. "Of course, if I knew it was going to be 3-D, would I have done a couple things differently? For sure. But we wouldn't have done (the conversion) if we didn't look at the movie and think we have enough fun things in it to take advantage of 3-D."
Among the dimensionalized fun? Jets that soar past moviegoers' heads, and a high-flying fight among ninjas in the Himalayas.
Fans online seem excited about "Retaliation," which stars Dwayne Johnson and Bruce Willis, along with Tatum and others. The movie site Fandango.com reports positive Twitter buzz for the film, which is the only new action offering on a weekend when many students are on spring break.