Thanks so much for trying it out and commenting! You want to hit the flying objects in front of you, just as they jump there, on the beat. I had them flying smoothly but started them jumping as a visual indicator of the beat. I added the beating heart right at the end of the jam.
I've been at Scratch 8 years and heard many times how hard it was to time events to an audio file. This was my first game jam so doing a rhythmic engine oe some kind of synced audio was already on my programing bucket list. Turned out to be pretty easy. I wasn't sure until the last few hours that I would even have a finished entry, kind hectic. Sooo little sleep :)
So finishing the jam with a working, fun game is great, but now I see tons of potential for this game as well as other rhythmic games. I've been playing guitar for 32 years, wait till you see my Jam Along project. You will be able to play chords or notes that are automatically adjusted to the key of the song. I've done recording and song trading already on Scratch so I see a lot of possibilities.