State of Decay has not released in Australia today due to a delay in the classification process, according to the studio.
Taking to Facebook, developers Undead Labs confirmed an Australian release for the open-world zombie survival game has been delayed due to classification procedures.
"We cannot ship to you tomorrow," the Facebook post reads. "We are still waiting for the Australian Ratings Board to certify the game, and unfortunately we have no control over their response time.
"As soon as we hear, we'll be shipping to you with the next game update. We will not leave you behind if we can help it!"
Every game released commercially in Australia is required to receive an age classification. Publishers normally submit titles well in advance to meet international release dates.
It's unlikely the delay is due to objectionable content: Australia introduced an R18+ classification earlier this year, resulting in titles previously banned in the region - such as Mortal Kombat - getting a new lease on life.
State of Decay is now available in Europe and North America for Xbox 360. A PC release is also forthcoming.