After a slow start as a 99c game, Temple Run - developed by husband and wife team Imangi Studios - has picked up a huge audience since it went free in September 2011.

According to TechCrunch, the 3D endless runner has had 20 million downloads to-date, with 7 million daily active users hooked.

In comparison, the latest figures from Zynga in December 2011 indicated it was catering for 13 million DAUs over its whole multiplatform portfolio.

Monkey see

Imangi co-founder Natalia Luckyanova revealed how designing the game to be fun, without requiring players to pay, has led to it becoming the top grossing iPhone game in the US, despite only 1 percent of its users opening their virtual wallets.

"There's no barrier to downloading it, and it can be fully played without having to buy anything," she said.

Luckyanova also explained how Twitter users helped spread the word, as players told each other about how scary the in-game monkey adversaries are. 

"A hit like this really funds your studio for years," she added.

"We're trying to keep it going by updating the game on a regular basis with new power-ups and characters to keep people engaged."

Going strong
Temple Run manages around 500,000 downloads a day, having been out for six months.

The team at Imangi has now expanded to three with a new artist being brought in, however the upcoming Android version of Temple Run will be outsourced.

Imangi's previous biggest hit was Harbor Master.

[source: TechCrunch]