"I've heard anecdotally that entrepreneurs are cautious about selling to Zynga," said an investment banker who works closely with gaming companies. "People would love to get acquired by a Google or Facebook because there's a certain cache and that's not there right now with Zynga." Angry Birds maker Rovio reportedly turned down a $2.25 billion acquisition offer from Zynga. Pincus' hard-driving personality and iron-fisted control over Zynga may also turn off employees. The CEO scored just a 46% approval rating among employees on career services firm Glassdoor, compared to an average approval rate of 62% of other chief execs on the site. "Talking to colleagues and former Zynga employees, Pincus is considered somewhat difficult by pretty much everyone that knows him," said Max Wolff, a senior research analyst at Green Crest Capital who does not know Pincus personally. Pincus isn't selling any shares in the IPO and will hold a class of shares that have 70 times more voting power than the common stock sold in the offering. Such a voting structure is unusual among tech companies, including newly public LinkedIn and Zillow ( Z) where certain shareholders had 10 times more voting power than public investors. This move was likely made by Pincus to keep a large pool of shareholders from holding too much power in the company. "He's the imperial CEO," said Wolff. "He's not going to lessen that white knuckle grip on voting rights in a post-IPO environment." Zynga did not respond for comment about this story. -- Written by Olivia Oran in New York. >To follow the writer on Twitter, go to http://twitter.com/Ozoran. >To submit a news tip, send an email to: firstname.lastname@example.org.