It takes all of five minutes for actor Jason Segel to drop his towel in his new movie Forgetting Sarah Marshall. In a scene that is both hilarious and heartbreaking, Segel’s character, Peter Bretter, is on the verge of being dumped by his longtime girlfriend, actress Sarah Marshall (Kristen Bell). However she won’t actually break up with him until he puts his clothes on and so...he doesn’t. As Peter sees it, "If I put my clothes on, it’s over.”

It’s over anyway. And so begins the journey of one man trying desperately to get over the girl who ripped out his heart. Peter heads to Hawaii only to show up at the same resort as his former flame and her new rockstar lover (Bristish stand-up Russel Brand). And while hardly original, this is the set-up for the new comedy written by Jason Segel, directed by first-timer Nicholas Stoller and produced by Judd Apatow.

It is clear to see why Apatow, the mind behind acclaimed hits Knocked Up and Superbad, has chosen Segel as his protégé. This film proves Segel is a genuine talent and while not yet in the same league as Apatow, he has that same wit in his writing which manages to be funny, provoking and generous all at once. Both have the ability to push the limits of this genre, a merging of the romantic and crude comedy, and come up with something unexpected and often humorously profound.

Segel is an appealing screen presence as well. The audience feels real empathy for Peter, a couch potato who is the music guy behind the CSI-like drama in which his girlfriend stars. He refers to his job as really turning out "dark, ominous sounds". On the side, he secretly composes a rock-opera for Dracula and this is where his heart lies.

The Apatow "regulars" are along for the ride: Paul Rudd as the stoned surf instructor, Jonah Hill as the creepy waiter/wannabe musician and Bill Hader as the stepbrother coaxing Peter to get on with his life. However the film’s funniest moments are stolen by a non-Apatow recruit. Brand is hilarious in his dead-on performance as the new-aged, oversexed Brit rocker, Aldous Snow, channeling Spinal Tap-type humour. One of the film’s funniest moments is when the waiter asks if Aldous has had a chance to listen to his demo tape and with perfect comic timing, Band indifferently replies, "I was going to… but then I just carried on livin’ my life."

The female characters in the film often seem in danger of becoming one-dimensional stereotypes but the writing and directing is too smart for that. Take the character of Sarah Marshall, played competently by Bell of Veronica Mars fame. For most of the film she seems to be a climber who cheated on her devoted, unglamorous boyfriend for the latest "it" celebrity. However the perspective is gently flipped at the end of the film and the audience understands that when they were together, Peter was often a mopey, self-absorbed slob. And while it’s not enough for the audience to root for her, at the very least, it reveals a touch of humanity to her character.

Similarly the firecracker performance by Mila Kunis (That 70s Show) of Rachel Jansen breaks free from the cliché of the pretty girl who helps Peter put his life back together. Kunis manages to find the perfect balance in her character between vulnerability and toughness. Many of the scenes between Kunis and Seger are genuinely touching.

The ending is a little clichéd, a little wimpy. And like many Apatow-related affairs, this could do with some editing but overall it is solidly entertaining and surprisingly sweet. The film ends in the same way as it opens, with Segel’s "parts" on display. However it is not Segel’s balls that he shows most in this film, it is his heart.