I really like the concept (actually had the same idea at first), but I have a bit of problems:
It feels very satisfying at first, but gets very unsatisfying when you have to clean that one spot you just cant get to due to the unresponsive controls. Just make the bar fill a little bit faster. And I dont no if you're new to game dev, but please also work on performance. I couldnt play it in the browser and even the downloadable version lagged, maybe thats why the controls were so unresponsive. But otherwise, very good.