James Cameron please take note: you don’t need to spend $200m to smack an audience’s gob. British writer-director Gareth Edwards challenges the conventional thinking that bigger is always better when it comes to special effects-laden science fiction films with his ultra-low-budget feature debut.

With a background in visual effects, Edwards sent ripples through the industry a couple of years ago by creating impressive digital trickery in his bedroom for a fraction of the normal cost. Now, the innovative filmmaker makes the seamless transition to the director’s chair with Monsters, a brilliantly executed thriller reminiscent of Cloverfield, which puts various multi-million dollar blockbusters to shame.

%movie(39088) Gareth Edwards and a small team, including two actors, travelled to Guatemala and Mexico with a skeletal script, a camera and boundless enthusiasm.

The crew found locations they loved and improvised scenes, intending to stitch everything together in the editing room, where hundreds of special effects would be added to evoke a futuristic world in which aliens and humans live side by side, segregated by massive concrete walls. This carefree approach to filmmaking appears to be a recipe for disaster but Edwards keeps control of the various elements with aplomb.

Monsters opens with a nail-biting night vision sequence and an attack on an armoured convoy We flashback to bright sunshine over Mexico where womanising newspaper photographer Andrew (Scoot McNairy) must help his boss’s daughter, Samantha (Whitney Able), return home to America. The ports are about to close and Andrew is told he must pay an extortionate fee to get Samantha on the last boat before the borders are locked down.

The only other option is to pay a smuggler to shepherd them through the infected zone where the tentacled aliens roam, which they are warned will be “a very difficult journey . . . very risky, very dangerous”.

Andrew and Samantha have no choice and head off into the wilderness, taking heed of one guide who tells them: “There are extra-terrestrials in the trees. All the trees are infected.” As they near the US border and freedom, the couple encounter the gargantuan beasts close-up and discover that the real monsters might just be mankind.

From its gripping opening to the heartbreaking conclusion, Monsters holds us in a vice-like grip as Gareth Edwards creates a richly detailed future reality, aided by strong performances from Scoot McNairy and Withney Able, who have since married.

The director orchestrates some terrific set pieces, including a nighttime boat ride that proves it’s not safe to go back in the water.

Apart from a few continuity errors, it’s difficult to tell that the film was made in such a haphazard fashion. Everything fits together snugly and the special effects are terrific, including the creatures revealed in their hulking glory in the final 30 minutes.

Megamind is a fast-paced computer animated adventure that asks if a villain could become a hero when the world is pitted against him. Megamind (voiced by Will Ferrell) is separated from his alien parents as a child and crash-lands on Earth, where he grows up in the Metro Prison For The Criminally Gifted. He destroys rival Metro Man, allowing him and his loyal henchman, Minion (David Cross), to take charge of Metro City but he soon finds life is empty with no one to fight.

Tom McGrath’s film appropriates elements from Shrek and The Incredibles and produces an entertaining hybrid that should have parents chuckling with glee.

However, with the focus on the unlikely romance and a noticeable absence of cute supporting characters, young audiences may be bored out of their no-so-mega minds.