Zynga shares have plummented 40% after the firm today announced a net loss of $22.8 million for the second quarter of 2012.
The Facebook games group said it faced "new short-term challenges" that impacted the business.
It also lowered its outlook for the rest of 2012, citing "delays in launching new games, a faster decline in existing web games due in part to a more challenging environment on the Facebook web platform, and reduced expectations for Draw Something."
Zynga boss Mark Pincus offered highlights of the firm's more positive performances. "The company achieved some significant milestones in the quarter including the launch of Bubble Safari, which is now the number one arcade game on Facebook, and the launch of The Ville, now the number two game behind Zynga Poker," he said.
"Our advertising business continued to show strong growth with revenue up 170% year-over-year. Our games reached record audiences, achieving over 300 million monthly active users. We grew our mobile footprint five-fold in the year to 33 million daily active users making Zynga the largest mobile gaming network.