Pros
Love the benefits and the salary. You learn a lot about the business quickly and a lot on how to build live products. It's a great way to start at a large company, especially since Zynga hires right out of college. If you're a go-getter, definitely a place to grow up your skills fast and get out of "entry" level. The new CEO is also proving to put in place business practices that I think will create stability in the company over all.
Cons
Zynga is VERY much a business (all companies are) and there is a lot of red tape when designing. Product Managers tend to own design at the end of the day and it can be disheartening. I minored in art, and the best thing I learned for a company like this is how to design within some parameter and make it amazing. It's an uphill struggle - but rewarding.