This seems like a prime candidate for some kind of high score game, though for as long as I played -- maybe 10 or 15 minutes -- there didn't seem to be any lose condition or score keeping. The graphics, sound and gameplay all fit together well, although I think I would have personally preferred an easier control scheme like WASD or arrows.
The only issue I noticed in particular was that sometimes barrels glitched out and became physical objects that the ants simply ignored. Maybe something to do with an ant "grabbing" the barrel but then becoming detached from it somehow. Eventually if they got bumped into the mushroom by another barrel being dragged by an ant they would get cleared out but in the longer term they really started to build up!