By BRIAN X. CHEN and JENNA WORTHAM

At a cocktail party on the second floor of the expensive Bowery Hotel in Manhattan on Thursday night, as trays of stuffed mushrooms and thinly sliced filet mignon circulated, Charles Forman was marveling at how quickly things can change.

“I had $1,700 in my bank account yesterday, and now I have a whole lot more,” Mr. Forman said.

The party was in celebration of Zynga’s purchase of Omgpop, a New York-based game maker founded by Mr. Forman, and it was extravagant to an extent that Omgpop’s employees could only have dreamed of until recently.

Omgpop had been limping along until Draw Something, a smartphone game it introduced just seven weeks ago, became a breakout hit. That drew the attention of Zynga, the maker of FarmVille and the current king of social games, which last week bought Omgpop for $180 million.

Draw Something transformed Omgpop from a little-known, nearly broke start-up into a must-have for an industry giant. The Zynga deal shows how companies are moving at Internet speed to stay on top of online trends, generating quick reversals of fortune.

“They bought a property that went from 0 to 60 in four seconds,” said Lewis Ward, a research analyst at IDC who focuses on the game industry.

Draw Something, a twist on Pictionary, involves making quick sketches that illustrate words and phrases like “swimming pool” and “starfish” for a friend to guess. It has been downloaded more than 35 million times since its release on Feb. 6, and players have generated more than a billion drawings, according to Zynga.

Mr. Forman, 32, was not directly involved in creating Draw Something. He left the company a year ago but kept his stake in it, and has been trying to get another start-up off the ground. In an interview he declined to say how much the deal was worth to him, but he said it was “way more” than $22 million. “It’s the kind of money where I’ll be wearing whatever I want when somebody invites me to a wedding.”

Omgpop did not start as a game company. Six years ago, Mr. Forman, a workout enthusiast whose Facebook page features a close-up of his abdominal muscles, founded what was then called I’m in Like With You, a dating site where users could essentially put themselves up for auction.

“The entire company started as a joke, honestly,” Mr. Forman said. He saw the site as a form of entertainment, he said, and only later realized that people were spending a lot of time on it. To capitalize on that audience, he converted it into a game site and renamed it Omgpop. “It’s one for the record books,” he said of the success of the company. “It is something I did not expect.”

Mr. Forman brought on Dan Porter, the former president of Teach for America who had experience at other start-ups, to be chief executive in December 2008.

Omgpop raised $17 million from investors and made about 35 games, but was not bringing in much revenue. In fact it was on track to run out of money by May, and probably would have shut down by now if not for the wild success of Draw Something, according to two former employees who were familiar with its finances but insisted on anonymity because of confidentiality agreements.

Mr. Porter, who will become Zynga’s general manager of operations in New York, declined to confirm this, but said: “Before this game came out, we raised a bunch of money, and we hadn’t made any hit games. That can’t go on forever.”

The company’s first drawing game, created by Mr. Forman and E. J. Mablekos, Omgpop’s chief technology officer, was a Web-based game called Draw My Thing. It was competitive, with a timer restricting how long a player could take to guess words, and participants would race to type the answer in a chat room.

Last fall, after Mr. Forman left the company on what he said were his own terms, Mr. Porter led a team of five in developing Draw Something.

He said some of his ideas for the game came from playing catch with his son and the son’s friend in Prospect Park in Brooklyn. He offered the boys ice cream if they could toss the football back and forth 100 times without dropping it.

“I had this moment where I thought, that’s exactly what the game is,” he said. “This game is like catch because we’re working collaboratively together to try to achieve something.” Draw Something has no time limits, and no real winning or losing.

On release day last month, Mr. Porter watched a counter ticking off the number of game downloads. It reached 30,000 that day — not too impressive. But about 10 days later, the downloads accelerated exponentially, soon topping a million.

People began posting their sketches on Twitter and Facebook, helping the game spread rapidly. And the game topped the Apple App Store charts, guaranteeing that many more people would hear of it and try it. Draw Something, offered as a $1 download and a free version with ads, both with the option of paying for extra features, began generating hundreds of thousands of dollars a day.

“It never slowed down,” Mr. Porter said. “The bigger it got, the bigger it got.”

That success attracted suitors, and soon executives of Zynga, which is based in San Francisco, were boarding planes for New York to talk about an acquisition. Mr. Ward of IDC said Zynga’s pursuit of Omgpop was a sign that it was emphasizing mobile apps, instead of the Facebook-based Web games that drove its initial success.

Zynga certainly wasted no time: the deal was announced last Wednesday, and by Thursday all 40 or so employees of Omgpop were already working for Zynga, having been briefed on company policies and their new health coverage. About 60 people attended the party that night, many of them members of the Omgpop crew, who congratulated one another with high-fives, hugs and celebratory photographs.

Mr. Porter said he was planning to take a family trip to Costa Rica before settling into his new job. Mr. Forman, who now works on Picturelife, a photo storage service, said that after the deal closed he was in such a daze that he wandered into traffic.

“I walked across the street, and all I heard was ‘honk,’ ” he said. “It was surreal.”