Dead Island players have spent 6,500 years in co-op sessions

Dead Island's co-operative mode is so popular that players have racked up over 57 million hours with it.

The startling figure, which equals about 6,500 years, was revealed by Deep Silver producer Guido Eickmeyer at GDC Europe, as reported by Eurogamer.

Eickmeyer said the co-op was the game's strongest selling point and contributed to its managing over 4 million sales despite a bit of a critical drubbing.

"This is why people are buying this game continuously, months later, and this is why people love the game," he said.

"It's why we've got a high user rating. It's the most exciting co-op experience that is on the market."

Sequel Dead Island: Riptide will focus on polishing up the co-op experience in addition to new features, and is expected to be more fully revealed later this month.