Was really into this, and thought your use of the flat line tone was the best of the bunch. Least favorite part was:

"I played out my heart
My heart on my sleeve
I've just been restarted
And soon I must leave you my dear"

The lyrics are fine...but I didn't care for the performance, and I didn't need to hear it 3 times. It was the only thing I didn't like about the entry though...so good job.

I know I would never write anything like this - but I like the fact that you have.

Man, that guitar tone is evil. Hey, defibrillation to go with the flatline tone, that's pretty cool. Hey, another song with shakers. This is getting old. Perhaps it wasn't a good idea to mention shakers in the title. If I have any complaints here, it's that the stopping heart comes a bit early, i.e. without anything plausibly leading up to it. I might have imagined something that starts out like that and then sort of semi-flashbacks or explains it. Ah well. So far this is the song that convinced me most in terms of how the challenge was integrated. Minor side note: singer's enunciation is a bit weird.