I'm not sure I get how to play the game - I understand you have to click on ghosts and play a melody (you said in a comment the melody has to start with F3 as is hinted on the start screen, is any notes fine as long as you start with F3 ?) but I'm not sure what the melody does - I think the game might benefit from a bit more feedback ?
The game seems to have a few bugs as well - at some point the ghosts just stop appearing just by continuing to click on them (before even trying out a melody), it lagged quite a few times (the screen freezes) and the countdown has a little issue where it starts at 23 then goes to 26 when the first ghost enters and starts decreasing normally from there (I played the web export)