Zerg Rush. The invasion of the "o"

Google always makes funny and interesting things. Now, you can find a really amusing game, like Starcraft: Zerg Rush.

You must be fast and have good reflexes, to erase the yellow and red "o" coming from the bigG logo. 

This is an ester egg hidden in the famous google search engine. Like "askew" and "do a barrel roll", it is really interesting. Try it writing  Zerg Rush