I played some Project DIVA PC made by gamemaster, and they had a very simple score editor where u could slow down the song and place the notes in real time. Does PPD has the same function or not ?

Yes !!
in "movie"
is the "record key" option
It is the same that PDP (Project Diva PC), but rather more and improved my more visual pleasure, and this can put any notes in real time, unlike the PDP XD

Thanks, but can you explain to me what to do, i just simply press record key and press the notes, but how can i slow down the movie ?