Quick and dirty
Nice game - love the art and style.
However I would have preferred some kind of upgrade mode - maybe the old granny could have been able to jump, run faster or hit enemies harder...
The other thing is the wave/round thing... maybe redefine to a continous growth of enemy strength rather than going from easy to hard every round.
For a game developped in 72 hours its really neat though.
Keep up the good work!