James Gunn on Trailer Pressures and Nearly Shelving the First ‘Guardians of the Galaxy’ Teaser

James Gunn is in the midst of a trailer-filled few weeks.

On Wednesday, Gunn debuted the first trailer for The Belko Experiment, a horror film he wrote and produced about a group of office employees forced into a deadly social experiment. Up next for Gunn is the first teaser trailer for Guardians of the Galaxy Vol. 2, which he told Heat Vision has been completed and will be released soon.

“Guardians is the harder one. With Belko, the premise is what people have to buy into,” Gunn said Wednesday night at a launch party for the trailer. “With Guardians, people really go through every single little shot and try to figure out what the movie’s about. And there’s a lot of mysteries in Guardians 2.”

Gunn said he spoke with Marvel’s marketing team on Tuesday about how much to show from the film, which debuted a sneak peek in October.

“We were talking about how much to give away — and we’re not going to give away very much,” said Gunn.

A challenge with crafting a Guardians of the Galaxy trailer is that each shot can literally reveal new worlds (and new spoilers), wheras Belko — which takes place in an office building — has a lot more flexibility with which parts of the film it can show without spoiling anything.

“You can show all sorts of stuff happening and it doesn’t really give away who lives, who dies, what the outcome is, what the mystery is,” says Gunn of the Belko trailer. “With Guardians, it’s such an emotional and physical journey, going to all these different places. It’s like, ‘God, do I really want to show this planet we go to in the middle of the movie? … Those are always hard choices to make.”

The Belko Experiment, from director Greg McLean, will be released March 17, 2017. Guardians of the Galaxy Vol. 2 hits theaters May 5, 2017.