The chickens are coming home to roost at the Finnish company behind the Angry Birds game.

Rovio Entertainment Oyj shares slumped more than 45% in Helsinki—the most since its initial public offering in September—after executives predicted 2018 sales and profit will come in far below previous estimates. Revenue will decline this year and adjusted profit will come in at only 9% to 11% of sales, the company said in advance of publishing its annual statement March 2.

Thursday’s numbers follow a third-quarter report that already left investors wondering how badly things are going at a company that has failed to replicate the success of Angry Birds. Asset manager FIM, one of whose funds holds Rovio shares, said that outlook was “hugely disappointing.”

“Often the market filters out some of the disappointment and gives some room for explanations,” said Aaron Kaartinen, an analyst at FIM. But because “the market isn’t listening to explanations” as more numbers are revealed, the initial bad reaction is “fully pricing into the stock.”

Finnish investors had high hopes for Rovio, which brightened the country’s tech landscape after Nokia Oyj lost its battle to dominate in consumer electronics. In September, the company sold shares to the public at 11.50 euros. To whip up excitement for its IPO, Rovio last year rented billboards and ran full-page newspaper ads. Even city buses were covered with images of Angry Birds.

Since then, the shares have lost about 50%.

Jolly Jam

Rovio’s main challenge seems to be its failure to repeat its Angry Birds success. Efforts to broaden the games portfolio have largely faltered, with titles such as Jolly Jam never taking off.

But the company has relied increasingly on its games unit, with licensing revenue continuing to plummet. It also operates in a tough market in which competitors need to spend growing amounts to get users to play their games and buy in-game merchandise and benefits.

Toy Income

Rovio’s user acquisition costs more than doubled in the fourth quarter, and were equal to 24% of its games unit revenue. Income from Angry Birds plush toys and other use of its brand fell more than 50% last quarter.

“They’ve had to own up to the fact that they’re having to buy revenue with expensive marketing spend,” Kaartinen said. “The games have to have genuine pull and at the moment, they just don’t really have such games.”

Ratings on Rovio shares were mostly positive this week. Four of the five analysts tracked by Bloomberg have been advising clients to buy. Based on their price targets, Rovio is currently more than 100% undervalued.

Kaartinen at FIM says Rovio has “positive Ebit, so they’re not in a crisis.”

“They may have thought that the well-known name helps get users to play the games, but this doesn’t seem to be the case,” he said. The game just has to be so good to bring in the big bucks.”