Not much of an observation, but I couldn’t fit it on Twitter. After seeing Batman Begins I wondered why there are no superheroes. After playing Arkham City I know: no respawns. In real life you’d just die.
All it takes is one moment of inattention, and it’d be worse if (as in Mirror’s Edge) a fall actually killed you.
(Corollary: maybe we’d get superheroes if we had backups, as in some SF futures, e.g. Stross’s Glasshouse. Though there’d be the annoying inconvenience that after a backup, unlike a respawn, you wouldn’t know what killed you.)