Killing mecha hawk

What is the point of tapping it out? The 2 times I've had mecha hawk or whatever it's name is :) I've received the "you won" with the same currency prize (within 10-20 I'm guessing) and the "you killed X robots" usually 32-35 with no flash. And I was inside the same ranges as before the mecha thing. So what does it give you or do or, other then tapping it with the others I see no difference in the game or winnings.

Am I missing something?