Themes/allegories/metaphors in media that just don't work because that thing exists in its universe? Final Fantasy 7. It's pretty obvious that mako energy is a metaphor for fossil fuels. Use too much mako energy and it will hurt the planet. But here's the thing, coal and oil exists in the FF7 world and Barret of all people is a coal miner.

Barret: Stop using metaphor coal. Use literal coal instead. AVALANCHE! 

Saving the planet my ass.