Mogworld
Because his books are so fun and accessible, many people who read Terry Pratchett's Discworld end up thinking "hey, this isn't so hard! I can write something like this, too!" They ignore just how truly difficult and impressive Pratchett's work is. It's chock full of memorable characters, surprisingly deep and innovative fantasy ideas, and wry observations about humanity, all while being deeply funny, AND flowing exceptionally well. Accomplishing all that is an exceptionally challenging task, no easier than writing a great work of serious literature.
If you don't believe me, look no further than Ben "Yahtzee" Croshaw's Mogworld, a book inspired by Discworld that is utter shit.
There are three elements to a book; its ideas and philosophy, entertainment value, and lastly, how good and articulate the writing is. Whereas Discworld excels in each category, Mogworld fails them.
With regards to ideas, Mogworld is an MMO which alternates between the point of view of characters within the game and that of its programmers. There are standard MMO quests to complete, the typical broad stereotypes, and the main characters grow sentient and realize what is going on. No character is particularly intelligent or even interesting, nor are there any unique fantasy ideas. It's all very rote and predictable.
As far as entertainment value, writing humor is damn hard, and Yahtzee is not up to the task. He goes for the cliched, low-hanging fruit (players are dumb and mindless when it comes to completing quests! Quests are repetitive! NPCs are illogical!), but presents it in too clumsy and ham-fisted a manner, killing any laughter.
Lastly, the writing is simply atrocious, and made me wonder if the book was edited at all. There are frequent spelling and grammar errors, bits of cringe-worthy dialogue, and laughable attempts at simile and metaphor. Yahtzee's description of a sunrise is more amateurish than similar attempts in many fanfics.
And that's what Mogworld reminds me of; a fanfiction by a huge Terry Pratchett fan. And far from the best one, too. Were it a free fanfic posted online, I would be far more generous in reviewing it as such. But when you decide to release it on Amazon and charge $10, I will take it seriously and judge it by the standards of quality fantasy novels. And this falls pitifully short.
On a personal note, when I read the book I was a fan of Yahtzee and his video game reviews, and I won't lie; I lost respect for him after completing it.
For someone who talks so much shit about lazy writing in games, and ruthlessly criticizes developers for making generic, substandard games for money, Yahtzee seems remarkably unconcerned about releasing an awful mess of a book (easily worse than any game he has reviewed) to make a buck off his fanbase.