As the old saying goes: "If it ain't broke, don't fix it."

We imagine that's what went through the mind of Kaimai's main director Peter Lau when he began crafting Spaced Invaders, a modern twist on the arcade classic Space Invaders that's been entertaining coin-op fans since 1978.

Lau spoke to us about how his idea came to fruition; respecting a classic; guest appearances; and his ambitious plans for a sequel.

AppSpy: Can you tell us a little bit about Spaced Invaders?

Peter: The game is set in three different stages and each stage has five levels. The first stage is set in a warehouse, the second in a nightclub, and the third is set at an outdoor festival.

You play as a DJ, whose aim is to stop the dancers / ravers from advancing towards you and your DJ station. Should they advance too far, they will damage your equipment, thereby stopping the music.

Each of the levels is accompanied by a different dance music track that was made specifically for the game.

AppSpy: One of the new features in Spaced Invaders is a crossfader. How does that work?

Peter: You use the crossfader on your DJ mixer to shoot at the advancing dancers / ravers while avoiding the glowsticks that they throw at you.

You either dodge the glowsticks or take shelter under the speakers in front of you to avoid being killed. Occasionally, a smiley face travels across the top of the screen: you have to shoot this in order for it to drop one of seven power-ups that you collect using your crossfader.

AppSpy: What inspired you to add this musical twist to Taito's '80s arcade classic?

Peter: I used to be a DJ - I love music, all music, but dance music has always been my favourite. Music unites people and makes them happy.

I was in a nightclub last year standing on a raised ledge and watching the crowd enjoy themselves when I came up with the idea for Spaced Invaders.

AppSpy: Are there any pressures or challenges involved going into a project where you're tasked with making changes to a classic like Space Invaders?

Peter: Absolutely, there are pressures. When you are working on a 'classic', you have to be acutely aware of how people will compare your game to the original.

You have to treat the franchise with respect and create a tribute rather than a rip-off. I think Spaced Invaders does this perfectly. We kept the basic format of Space Invaders, but brought it right up to date for today's gamers.

AppSpy: You worked with Mike Di Scala on the music for Spaced Invaders? How did he get involved with the project?

Peter: I've known Mike - one of England's best DJs and music makers - for many years, so it was an obvious choice to ask him to produce the music for my game.

Mike's group Ultrabeat had a #2 hit in the UK charts in 2003 with 'Pretty Green Eyes'. He is a well-known and much-loved DJ in England.

Mike jumped at the chance to make the music in Spaced Invaders. In my eyes, it was a massive coup for me to get Mike to write and produce the music, and it was also a chance for the rest of the world to hear a little bit of Mike's music.

AppSpy: Who else worked on the game as well?

Peter: I came up with the concept for the game, but I used a company in Birmingham called MS Internet to actually make the game for me.

All of the game design for Spaced Invaders was carried out by Ben Dunn. Kristofer Whitford designed and animated the characters, while Martin Saunders took care of all the code.

AppSpy: Are there any updates planned for Spaced Invaders, e.g. new tracks and levels, or would you prefer to include new features in a sequel instead?

Peter: I think the plans are to do a sequel rather than updates. What I would like to do is to go to different clubs all over the world, photograph what it actually looks like from behind the DJ station, and transfer this image into the new game for a more authentic gaming experience.

Each stage could be set in a different club in different cities from around the world.

There will also be a lot more music in the sequel, with your getting the choice of the type of music you would like to play the game to.

AppSpy: What are the chances of the game being ported to other mobile formats, such as Android or Windows Phone?

Peter: That was one of my main priorities when I came up with the idea for this game. I want it to be available to gamers across all formats, so watch out, Android: Spaced Invaders is coming to get ya'!

Spaced Invaders is out now for iOS, priced at 69p / 99c [iTunes link].