The Flash finally races into theaters this week, and DC fans will be hit with a bevy of cameos and surprise returns that'll excite die-hard fans. The film's director, Andy Muschietti, recently spoke about the creative control he was given with these cameos and it may surprise you just how much freedom he was given.

Speaking with Total Film, Andy and Barbara Muschietti spoke specifically about the cameos in the film and how much leeway they were given by the higher-ups at DC. It started small, “We brought [spoiler] in, there really were no rules,” said Barbara.

But it got bigger and crazier — almost as if they lived by the words spoken by Michael Keaton's Batman in the 1989 movie (and The Flash), “You wanna get nuts? Let's get nuts!” — as the cameos in The Flash are a mix between old classics and even some films that were never made.

“As long as they were DC characters, everything was allowed,” said Andy.

Andy Muschietti then revealed that took those parameters and ran with it: “I made a list of superheroes that I love, that I would love to see, and it was a long list. And then, for time matters, for pacing, we had to shortlist that a little bit. The movie is the result of that shortlist, but I'm pretty thrilled by the superheroes that we gather.”

So there you have it — it looks like Muschietti was given the reins when it came to implementing the characters he wanted in The Flash. It is a multidimensional adventure, I guess, so it makes sense that they were able to incorporate anyone that they want. The cameos in the film made the audience at my screening clap and go crazy with each one, so hopefully audiences enjoy them when the film officially opens this week.

The Flash will be released on June 16.