9. T-073-M - Ghostrunner
Frenetic action-platformer Ghostrunner pissed everyone off with its migraine-inducing first boss battle against computer mainframe T-073-M aka "The Gatekeeper."
Like many of the bosses on this list, T-073-M was clearly a skill check boss intended to test your mastery of the game's mechanics up to this point, and it sure is a doozy alright.
The Gatekeeper will use lasers, fire, and then lasers and fire to keep you at bay, requiring players to basically trial-and-error their way through its attack patterns, in turn spending way too damn long learning how to beat the damn thing.
You might literally die hundreds of times taking it on, and though defeating the Gatekeeper means you've basically beaten Ghostrunner's toughest challenge, it just might piss you off enough to put the game down entirely.
It's certainly a unique and creative boss battle, but nerfing the difficulty slightly wouldn't have been such a bad thing, would it?