I came from the video where you said you wanted feedback. I have a few thoughts:
Awesome idea! The music and art are great! And the gameplay is compelling! I loved the story bits in between each level, and how it added context to the gameplay.
But the game got too hard too fast. I went from brushing static non-killer teeth to facing an entire missile wielding army in the very next level. And after I beat the army of killer teeth (dying about 4 times) I found myself in an equally hard level, if not harder. That is to say, the game has no difficulty curve, it's just a difficulty ramp. It only goes up, and fast. I would prefer if there was a buildup of tension, like there currently is but with a intermediary level of less lethal teeth of a lower quantity, then after the really hard level the difficulty could go back down (release the tension) to a less difficult level. That difficulty curve is the one thing no player will be able to ignore, it's an essential part of the experience.
Something I would just personally like is if during the period where all the teeth are shaking about to burst into flies, it would feel good if cleaning the teeth prevents them from becoming flies. That makes the prelude to each battle about cleaning as many teeth as possible before they have a chance to attack you. I tried that intuitively but it didn't seem to work. I could see how that could break the game with the upgrades later on though.
In any case this was really fun! Well, until I couldn't handle the difficulty. But I still really enjoyed it! I'll probably go into squeaky clean mode to try and finish.
Edit: Man. I couldn't beat the boss on squeaky clean mode, maybe the problem is just me.