Really interesting mechanic! How did you think of it? I wouldn't have predicted when starting the game that I'd be able to walk on the ant trail. Nice one. The movement and jumping felt really natural and accurate. The graphics are cute and I have not yet progressed to level 9 :)
I think the difficulty ramps up at about the right rate. I can't think of anything I'd immediately change, look forward to seeing where you take this. Nice work!