Image caption Iron Sky was part funded by fan contributions

As film plots go, comedy Iron Sky is a headline-grabber: in 1945 the Nazis went to the Moon. In 2018, they are coming back to invade Earth. No wonder since its first screening at the Berlin Film Festival, it has caused both comment and controversy.

But is the low-budget production, made by Finnish director Timo Vuorensola, actually worth the hype?

"It's a tremendously politically incorrect film," says Vuorensola. "I wanted to make something fun. We're not aiming to preach here, and we're not being offensive, but we do have a message."

The film starts in 2018, with an American landing on the Moon, staged to help secure the current Sarah Palin-esque president a re-election. The astronauts are captured by a group of Nazis, who have been hiding on the dark side of the Moon since the end of World War II.

They are plotting an invasion of Earth. This thrills the US president, who believes a war will automatically win her another term in office.

The best response has been from young Germans, who have nothing to do with the Nazi era - to them, the Nazis are just historical, but it's still a big taboo subject over there Timo Vuorensola

"Obviously, it's got something to say about war-mongering," says Vuorensola.

"From my point of view, I am frightened by the rhetoric of international politics right now. It has echoes of the 1930s and the rise of fascism. However, it's up to audiences if they want to grab that message."

Vuorensola has a reputation as a sci-fi fanatic - he has previously made cult parodies Star Wreck V:Lost Contact and Star Wreck:In the Pirkinning. He says it's no surprise he looked to space for inspiration for Iron Sky.

"The Moon is mysterious, and I love the phrase 'dark side of the Moon'. There's an urban myth that the Nazis had a space programme which was just more than trying to launch a rocket.

"There's a conspiracy theory that the Nazis made lots of secret space experiments and whatever they built, at the end of the war, it just vanished. Did it go to the USA? The USSR? No-one knows. So a whole mythology has grown up around the subject.

"And it's not so far-fetched they could have gone to live on the Moon. Twenty years after the Nazi era, ice was found there, and algae. If you knew what you were doing, you could survive.

"Of course, I am trying to look at a crazy topic with a straight face."

Image caption German actor Udo Kier is the best known member of the Iron Sky cast

Vuornesola says he took a chance by giving the film its world premiere in Germany but says despite the subject matter the response from audiences there has been warm.

The film does have several German stars in it, including cult horror actor Udo Kier, who was born towards the end of the war, in 1944.

"The German cast did ask their agents to read the script before signing up, and I can't blame them. Ten or 15 years ago it wouldn't have been possible to do this film in Germany.

"It's probably still not possible if you're German. You need some distance still in order to make fun of the Third Reich.

"The best response has been from young Germans, who have nothing to do with the Nazi era. To them, the Nazis are just historical, but it's still a big taboo subject over there. I also want to make it clear that in this film, we might make fun of the Nazis, but we never, ever poke fun at their victims."

Contemporary issues

Media playback is unsupported on your device Media caption Director Timo Vuorensola: "We thought this was a topic that would be interesting"

Since its premiere in February, Iron Sky has been sold in 70 countries, including the UK, and the Iron Sky trailer has been viewed online more than seven million times - breaking records for an independent film.

Its budget was seven million euros, which considering the level of special effects needed was tiny at best. One million euros was raised online by fans.

"We managed," the director says. "I am used to making tiny films. The fans' support for the project was incredible, and actually once they had given a million, we managed to secure the rest of the budget by the more traditional means.

"Executives told us it was their best pitch in years. Well - it's a pretty simple tagline, isn't it?"

Reviews, however have been mixed. The Guardian said "nothing about this Finnish derived space-oddity quite matches the genius of its tagline".

Time Out comments: "The sight of space Nazis powering down a lunar inspired autobahn is especially memorable. The problem is the script, which at best feels like an irritatingly self-aware B-Movie pastiche."

That has not stopped Vuorensola and his production team from plotting both an Iron Sky prequel and a sequel, which was recently announced at this year's Cannes Film Festival. Will audiences still be interested?

"I hope so. Iron Sky is a contemporary film, more contemporary now than when we made it. Look at the rise of the far right in places like France and Greece.

"We've gone through it in Finland too. There's a lot of unemployment and financial hardship, and just like in the 1930s, outsiders are getting blamed.

"In the film, I put some words that the Nazi Joseph Goebbels actually spoke, and put them into the mouth of the US president. We are still speaking the same nonsense as we did then.

"Nobody escapes in this film. The Nazis are just used to reveal the true colours of all the politicians in this story."

Iron Sky is on limited release in the UK and available on DVD this week.