I know it's a perversion of the English language to say so, but it's hard not to think of Colossal as a "very unique" movie. (In fact, Microsoft Word is telling me right now to "consider using concise language.") It's a romantic comedy about a woman, Gloria (Anne Hathaway), who flees from New York City back to her rustic hometown, where she bumps into a guy (Jason Sudeikis) she used to know. It's also a movie about a giant monster wreaking havoc on downtown Seoul. It's two great tastes that go great together—especially once we learn that Gloria has an unexplained connection to the kaiju in question, able to somehow control its movements from half a world away.

It all makes sense eventually, or at least as much sense as it needs to. This sort of genre tweaking is nothing new to director Nacho Vigalondo. The Spanish filmmaker's first feature, 2007's Timecrimes, was a micro-budgeted time-travel thriller with a sleeveful of surprises. His next film, 2011's Extraterrestrial, asked the question "What would you do if there was an alien invasion on the day you met the girl of your dreams?"

I talked with Vigalondo by phone about his approach to filmmaking and how cool it is to work with movie stars.

Are you intentionally trying to play with genre tropes in your movies, or is that just where your mind goes when it roams?

I recommend keeping a significant amount of innocence when making a film. Don't think about yourself. Don't think about the kind of identity that you want to achieve. Just make something that's going to be cool on-screen. Try to amuse yourself in the most innocent way—like playing with toys. When I started writing this film, it wasn't me trying to defy expectations. I was just thinking, "Wouldn't it be cool if this happened? Wouldn't it be amazing to see that on the screen?"

Colossal is aptly named, since it's your biggest-budget movie to date and has a couple bona fide movie stars in it. Was that challenging?

All my other movies have been small, but that's how I write it. I like to have these confined scenarios, just a few characters. In this case, the stakes were bigger, but it didn't feel that different. When you're on set, it's about what should be on camera, and what comes after and what comes before in the cut. I think that that's the key. That will never change.

What about working with Anne Hathaway and Jason Sudeikis? They aren't exactly known for their monster-movie cred.

This was a situation in which the actors came to me, which was amazing. They felt like the perfect choice, not only because of the way they work on-screen but also because of the way they resonate. When you see Jason Sudeikis and Anne Hathaway on the poster, you may think of the kind of movies Colossal is trying to attack. When the synopsis went public, some people thought I was making a spoof of monster movies. It is nothing but a love letter to monster movies. What I am making a comment on is romantic comedies.

When that synopsis did go public, there was a lawsuit from the people who own Godzilla. Did you worry this movie would never happen?

I had the fear you always have when you're making a movie, because things can go wrong in so many ways. But I felt protected from the very moment that Anne Hathaway wanted to play the role. She was never worried about anything. Once Anne Hathaway wants to make a movie like this, the movie is gonna get made. If you like the movie, you have a lot of thanks to give her.