A mobile phone game that was first created in 2003 has been reworked to try and raise awareness of the plight of gorillas in Rwanda.

The new, and free, version of Silverback simulates the lives of the animals in their natural habitat in Volcanoes National Park in northern Rwanda.

Ken Banks, who designed the game in association with campaign group Flora And Fauna International (FFI), told BBC World Service's Digital Planet programme that he made sure that the game was "rooted in some kind of reality".

So it's not a rip-off of Donkey Kong but actually gives a sense of what the gorillas actually do.

Banks explains: "In the first level, you start as a baby gorilla - you are lost, you have to find your family and make your way back".

"Then on subsequent levels you have to fend off rival silverbacks, find yourself a mate, start your own family, lead them to safety, avoid poachers and snares."

"We try to lead people through the life of a mountain gorilla to give them a sense of the challenges they face both naturally and through human threat."

The game download is free but the team behind it hopes that it'll encourage people to rummage in their wallets and support the cause.