Not exactly the way it would work, basically the way things are valued you can't necessarily get that much money for them. In the ideal world there would be a business there too.
Now all of this is moot if Zynga is making enough money to pay the bills, doesn't matter what their stock price is if they don't have to sell stock to raise money. So the thing to look at is when their obligations exceed their assets, that is when they are 'upside down' in the lingo. Very hard to recover from that because you can't even borrow money temporarily when that happens, you have to save money, then use the money you saved to do the thing you wanted to do, rinse and repeat and that removes your ability to react quickly.
Zynga is structured such that Mark Pincus has a majority of the voting shares (50.15% to be exact). This means he cannot be fired nor can any takeover occur without his consent.
I don't think it's undervalued by enough for that to work, yet. According to this report, the stock is currently priced 9.5% below book value, but in a hostile takeover the acquirer typically needs to pay a significant premium over current share price, in the range of 10-25%, in order to rapidly acquire a bunch of shares.