The angry birds at Rovio Entertainment Oy are set to lay a golden egg for the company’s founders.

The firm is planning an initial public offering as early as next month that could value the maker of the Angry Birds mobile games and movie at about $2 billion, said people familiar with the matter.

The company could raise about $400 million from a local market listing, the people said, asking not to be identified as the details aren’t public. No final decisions have been made and the company could also choose to stay private for longer, they said.

A listing would test investors’ appetite for entertainment software, a group whose shares have declined an average of 18 percent from their offer prices following IPOs this year, according to data compiled by Bloomberg.

That’s because mobile game makers…