Last year’s comedy The Hangover was an unexpected surprise. It was silly beyond words, but audiences responded to it in their droves. Using the same formula, its director Todd Phillips will no doubt be hoping for the same kind of success with Due Date.

It’s understandable that most fathers want to be there for the birth of their first-born; due to the carnage involved it’s no surprise that they’re less eager to attend subsequent births. For peter Highman (Robert Downey Jr.) though, he definitely positively wants to be there to see his first baby born. Unfortunately for him, he’s away from home on business, but with his wife not due for another week or so it’s no biggie.

He hits a snag on board a flight back home though, when he gets into a conversation with fellow passenger Ethan Tremblay (Zack Galifianakis) that finds them both kicked off the flight. Not only that, but Peter finds himself on the No Fly List, making it impossible to take a plane home. When his wallet also goes missing he has no other choice but to take up Ethan’s offer of joining him and his pooch Sonny in his hired car for the cross-country trip.

With Peter’s wife ready to go into labour any day, he’s eager to get home as soon as possible. But with a lot of ground to cover, the trio find the journey ahead far from being a smooth ride.

I don't know about you but what do you say we ditch the other guy for the sequel? Me too.

No prizes then for guessing this is a road movie. Phillips is clearly a fan of the genre as he also directed 2000’s dreadful Road Trip; to be fair it wasn’t all his un-doing as it suffered from the kiss-of-death casting of Seann William Scott. Thankfully going down the same road has at least resulted in a better film, but how much better?

Originality. Acerbic wit. Charm. Three things that Due Date is complete devoid of. The story is pulled around more than Stretch Armstrong, lacking any connection to common sense. It’s simply a poorly constructed ruse to get Downey Jr. and Galifianakis in close quarters for an hour and a half.

The only real surprise that it shows is in having Downey’s character being totally unlikeable. This may have been seen, on paper at least, as a bit of a twist on the road trip dynamic, but it goes woefully wrong on screen. Peter suffers considerably from the ineptitude of Ethan; however, as he behaves so appallingly throughout himself, it’s difficult for an audience to root for him or give a hoot as to his eventual outcome. With so many examples of anti-social behaviour, it could be argued that he deserves a hell of a lot more in the way of mishaps. Can an audience care for such an arrogant and charmless character? No, they can’t. It’s difficult to see what Downey saw in Peter in the first place, as he has no redeeming features. It may have been an attempt to give his character depth, but it’s only resulted in the complete opposite, making him shallow and ugly. Perhaps spending all that time in an iron costume has somehow clouded his creative judgement.

Galifianakis can be grateful to Downey at least, as he only manages to make his performance as Ethan more likeable. In fact this road movie is a one way street serving as nothing more than a star vehicle for Galifianakis. He was the best thing in The Hangover and he’s done the same thing here. It cements his position as a leading comic actor capable of opening a film, which suggests he’ll be spending less time between two ferns in the future.

Perhaps the pressure got to Phillips; after all The Hangover ‘s success caught a lot of people by surprise. He tries far too hard over and over to have a defining comic moment; every gag is an attempt to match the hair gel scene of There’s Something About Mary, by trying to be iconic. Unfortunately for him however, he fails every time. That’s not to say that there aren’t any genuinely amusing moments; there’s certainly enough here to keep a crowd happy. Where it falls woefully short however is by pushing the warped humour at the expense of the two main character’s relationship. There’s no real sense of friendship or warmth between them; even the film’s end attempts to reveal a true bond between the pair, but it’s ultimately all too tokenistic and fake to be considered honest.

Those that flocked to The Hangover will no doubt do the same for this and therefore make it a similar success. What Phillips will need to be wary of, however, is audiences coming away with the strong feeling that Due Date, more often than not, fails to deliver.