I enjoyed this parody -- while hardly the best bit of comedic fiction ever written, it was overall good, and at times shined.
The basic story of Harry Potter is mirrored, but that mirror is quite warped. Henry Potty, the chosen boy, with forehead mark (lipstick). His friends Horrendous Gangrene and Really Wimpy. Evil Lord Revolting. Chickenfeet Academy. Gay headmaster Bumbling Bore, who by the way is gay. Professor Sniffly Snort, of unclear alliance and poor nasal health. Henry must quest for and destroy the hidden Plot Devices before he meeting the Forces of Dimness in a climactic battle. You get the idea.
The formula of corrupting names to create parody characters is tried-and-true, and gets the job done. Lots of puns, some good, some bad, some deliciously awful. Some gross-out and bathroom humor, of varying degrees of intelligence (a poop joke can be witty, but most of the time it's just a poop joke). Some of the gags become a bit tired at times (e.g., repeated descriptions of how disgusting Lord Revolting is). There's a lot of pop culture references, some of which were quite unexpected (that's a good thing). And there are moments of real insight into what drives a popular fantasy franchise, and the fandom and fame that grows-up around them.
At its worst parts, it's straight juvenile humor, but at it's best, the author approaches the literary flavor and comedic sense of the likes of Terry Pratchett.
Those who think the author hates Harry Potter need to look at her C.V.: She's written and presented on several Potter-related topics, and clearly knows and admires Rowling's body of work. You can't do good parody without understanding the source material, and you can't truly understand something unless you love it.