It's extremely funny to bash out through the hordes of your unsuspected enemies at full charge :) Thank you for making me experience this childlike feeling! But I've found that it also became repetitive quite quick. After this point you have to run through your enemies not because you are having fun, but in order to collect more gold and pump yourself up with new upgrades. The game starts exploiting the very sense of kinetic freedom it produces in order to create seemingly endless loop of accumulation and waste.
This game, just as your other game, Tap Heroes, is wonderful at creating fun, travesty kinetic experiences (in TH it was punching cardboard/sock puppet, here - bashing through the obstacles like a mad ram :)), and retro graphics and music also help at creating this arcade-like experience. But repetitive factor comes in place, and pushes the fun to its excess, turning it into a tiresome chore.