Look at the first two words of the title: “It’s on”
“like donkey kong” just completes a phrase.
http://lmgtfy.com/?q=it%27s+on+like+donkey+kong
its on like donkey kong
A phrase to denote that its time to throw down or compete at a high level; something is about to go down. The use of the comical video game character Donkey Kong provides comic relief but the phrase itself has greater or more significance than simply its on.