It's very fun!
I reached about 15k
Although maybe you should add something to stop the player from rageclick into oblivion, is what I did!
Was fun to do though, don't know if was the spawn rate or something but when doing that and going in the middle nothing really stopped me, besides I stopped from time to time to get some more energy.
Also, I loved the art!
PD: For the guy that reached to 25k, I got 34k