Some bugs are worse than others; while we're used to seeing the odd graphical or audio issue in our games, these don't ordinarily render a game unwinnable – but it would seem that Paper Mario: The Origami King is saddled with a design hiccup which means you can't complete it.
The issue – as detailed in the video below – involves the section where you are tasked with visiting four spas in the Shangri-Spa area in order to gain access to a secret fifth spa. The issue is that once the NPC guarding the entrance asks to see the membership card required to enter, it is removed from your inventory entirely – so if you exit the area for whatever reason, you can no longer gain access because you don't have the membership card, nor does the NPC remember taking it from you; it's also not possible to obtain a replacement.
To make matters worse, this area is found towards the end of the game, and if you unwittingly save your progress after making this mistake, you'll have to restart the entire game from scratch as it's not possible to roll back to earlier saves, as you can in, say, Zelda: Breath of the Wild. That means losing around 30 hours of progress.
But that's not all – according to Gaming Reinvented, second game design issue exists which locks players out of obtaining 100% completion. This one is present in the Snif/Shroom City area, where, if you turn off the water in the hotel and leave without freeing the Toad which is being used as a surfboard, it’s impossible to liberate that Toad later on in the game. While this isn't as dramatic an issue as you can still finish the game, you won't get that all-important 100% rating.
We'd imagine that Nintendo will fix both of these problems pretty quickly, but let us know if you've fallen foul of this design glitch by posting a comment below.