I thought I had seen the worst rendition of that song ever.... it was by a local band (well, from Newton Stewart) called Project Killbot. They did half, and then switched to a 'metal' version of 'Hit Me Baby One More Time' (which had a growled chorus with the keyboard player doing backing vox like the guy in this video except falsetto), then switched back to 'Final Countdown' again. They also played a cover of the Super Mario theme.
All this, and yet the version in the video was worse.
I didn't think it would be possible to make the keyboards any cheesier, but I guess I was wrong! The singer sucked gargantuan toad anus and the whole band seems like they can't play instuments. Very funny stuff. Gave me a giggle and a couple LMAO's.