What makes a great Indie video game?

Destiny, a computer game set 700 years in the future during a war between humans and aliens cost a staggering $500m to make and distribute.

With production figures like that, it's no surprise that the industry is estimated to be worth around $100bn a year.

So what makes a game successful? It's not all about fighting, shooting and chasing, according to developers in the more cutting edge indie sector of the market.

The odd, the bizarre and the downright creepy are just as likely to be big hits, as Elizabeth Hotson found out at a specialist games event in London.