It's simply expected that video games save the toughest, most bastardly challenge for last. After a game's worth of tooling the player up and teaching them all the ropes, feed them to a pain-in-the-arse final boss to make sure they earn that precious end credits roll, right?
But that's not always the case - sometimes the trickiest challenge comes much earlier than the end, and sometimes it's not even another boss, but the damn game mechanics themselves.
After all, how can you even have a hope in hell of taking on the final boss if you haven't mastered the basics? But sometimes "the basics"? They're not so basic.
These eight video games all offered up brain-snappingly challenging mechanics which left many ready to tap out and move on long before they reached that final boss who, by comparison, was a certifiable cakewalk.
In these games, the trickiest mechanics were the real final boss, if we're being totally honest with ourselves, because nothing came close to matching their level of piss-boiling frustration. If you could make head or tail of these finicky gameplay flourishes, though, you were sorted...
8. The Portal Gun - Portal
The Portal games are two of the most ingeniously noodle-baking puzzle-platformers ever made, with players forced to use the Portal Gun - or, er, the Aperture Science Handheld Portal Device - in order to progress.
The Portal Gun can generate portals between two spaces, and so players are charged with finding creative ways to fire the gun in order to traverse the game's increasingly tricky test chambers.
This mechanic is the game, basically - a series of physics-based challenges which will require you to use the Portal Gun to manipulate objects in the environment and exploit momentum to fling yourself around like a meaty rocket.
It's brilliant but positively brain-breaking, especially when the game first hit the market back in 2007, where there was simply nothing like it.
But once you've actually gotten to grips with the particulars of using the Portal Gun, the climactic boss battle against rogue AI GLaDOS is pretty much a breeze.
By this point, having spent hours using the Portal Gun in myriad barmy ways, GLaDOS doesn't offer much of a challenge.
You simply need to create portals to fire GLaDOS' own rockets back at her, collect her broken parts as they fall off, and throw them in the incinerator - repeatedly until she finally croaks.
Given some of the utterly headache-inducing portal puzzles throughout the game leading up to this, the final encounter feels, dare one say it, trivial by comparison.