Bewell_inside1Zynga better brace for its newest rival, the German manufacturing behemoth Siemens, which is reinventing itself as a social gaming startup with its first title out today, “Plantville.”

While Zynga makes money by selling virtual items in their games, say tractors, Siemens won’t charge for any items and just wants to muster up interest in “math, science and technology while inspiring the next generation of plant managers.” Siemens, keep in mind, has the edge of having sold tractors in real life.

And just because Plantville is an educational game, which could scare away users,  it doesn’t mean Zynga shouldn’t be shaking in its boots.

The game, which launched this morning, has already spread to 27 countries and has more than 1,000 players, says Tom Varney, head of marketing communications for Siemens Industry.

Zynga might think it’s big, with 1500 employees and a $9 billion valuation, but it’s dwarfed by Siemens, which has a whopping 420,000 employees (who are allowed to play the game at work) and pulled in $75 billion in sales last year. While Zynga is known for acquiring competitors, this might just be one company that’s too rich for it.