Love 'em or hate 'em, the idea of a boss battle - the hardened version of a standard enemy or a wall of difficulty you've got to surmount - is in gaming's DNA. For about as long as man could put finger to key and create code, they birthed challenge, and as that was the case, we only played games for the sake of testing our mettle against all sorts of digital concoctions designed to stretch your patience to the max (after all, arcades weren't going to hoover up quarters if you could play something once and then leave), but more recently, designs have changed.
A boss battle could relate entirely to the narrative, might have your legs for breakfast as you attempt to figure out a specific trick to defeating them, could simply be a bullet-sponge that laughs at your pathetic attempts to take it down, or a mix of all four.
Gaming as a medium is finally entering a time where technological ambition matches developer's intentions perfectly. It can create fascinating fusions of multiple mediums like Quantum Break... or it can be used to test that aforementioned mettle to breaking point.
Either way, we've come an awful long way, and these are the guys that continue to help give gaming its immortal identity as the most engaging medium of all time...
What It Did First: Popularised quick-time events as a means of defeating a boss.
Quick-time events have been used for everything from caving someone's skull in to performing hilariously-animated sex positions, but they all had to start somewhere. As Shenmue proved through its weirdly memorable forklift levels, simply adding a few button prompts onscreen during what would otherwise be a non-interactive segment, enhances the engagement tenfold.
Apply that ideology to boss battles, and God of War's terrific fight against the Hydra is one of the best. Button-mashing as a means to control scripted action was a new concept at the beginning of the 2000s, but doing so to pry open its jaws or skewer its eyes with a flaming chain-blade felt spectacular.
Since then, everything from Halo 4 to Beyond: Two Souls has implemented some sort of quick-time event boss - even if it then segues into regular gameplay. Other games may have done it first, but God of War etched itself into the history books as the one that got it right first time.