A few bugs/unintended features.
1. The instructions can't be closed once opened. At least, I couldn't find a way to close them.
2. The damaging area doesn't follow the vfx (darkened circle), but follows the cursor. This is visually confusing. Either have the vfx follow the cursor without a max speed, or else have the effect follow the vfx.
3. There is some sort of invincible stack of signs in the center of the play area which consists of all three types of sign.