Though they might not have been commercially successful — at least in the conventional sense — the comedy troupe The Lonely Island has been responsible for two of the last decade’s best and most ridiculous comedies. In 2007, Akiva Schaeffer directed Hot Rod, which starred fellow Islander Andy Samberg, and, in 2010, Jorma Taccone directed MacGruber. Both films were instantly cult classics, stylized parodies that made the most of the trio’s signature silliness.

Though he’s the biggest star of the group, Andy Samberg has fared less well on his own (ahem, That’s My Boy). He co-produced his new HBO mockumentary 7 Days In Hell, which is now available on HBOGo, with writer Murray Miller (American Dad, Girls), and the result, unfortunately, doesn’t break the streak. While 7 Days in Hell is stuffed with cameos — John McEnroe, Serena Williams, Chris Evert, Will Forte, a wildly unfunny Fred Armisen — celebrity drop-ins are not enough to give the mockumentary, which is filled with gay jokes, momentum. Samberg, as a Swedish exile, wields his Swedish chef Muppet impression like a racquet, but it doesn’t have strings.

7 Days in Hell takes a pretty solid premise — a marathon tennis match no doubt inspired by John Isner and Nicholas Mahut’s epic match at 2010’s Wimbledon — and fills it with cliches. Samberg’s Agassi-inspired character struts, snorts, and fucks his way to acclaim, but he’s not particularly likeable or outrageous. As for Kit Harrington’s performance as the rock-dumb British tennis prodigy Charles Poole… well, let’s just say that if there’s anybody who really needs to hope that Jon Snow isn’t dead, it’s Kit Harrington.

Featuring a number of bizarre pivots, including a weird left-turn where the mockumentary seemingly becomes all about a oddball courtroom sketch artist, 7 Days of Hell, much like a 7-day tennis match, is a test of endurance.

Serena Williams deserves better than this.