King Digital Entertainment officially began life as a publicly traded company on Wednesday, but plunged below its initial pricing levels on the New York Stock Exchange, after weeks of breathless publicity.

On Tuesday, the maker of the addictive mobile game "Candy Crush" priced its shares at $22.50 after the U.S. markets closed. The gaming company, listed as "KING" on the Big Board, issued 22.2 million shares, giving the initial public offering (IPO) an initial value of just under $500 million.

Yet just hours after pricing, investors appeared to lose their sweet tooth. The game maker, which first rose to prominence as a Facebook application, saw its stock open on the NYSE at $20.50—but quickly swan-dived by nearly 16 percent as buzz over the hotly awaited IPO began to fade. In heavy trading volume, the stock tumbled as low as $19 per share.

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Ricardo Zacconi, King's co-founder and CEO, put the best face on the stock's damp debut. He told CNBC's "Squawk on the Street" the IPO was "the start of a marathon, and I think the opportunity is great." The growing emphasis on mobile technology gives his company an edge, he said: "I'm very excited."

Others, however, were far less impressed.

"It's a Stephen King horror story," quipped CNBC's Jim Cramer, referencing the master of the horror genre and some of his most famous books. "It might be 'Misery,' it could be even 'Cujo.' "