Greg McLean, who's known for his vacation-gone-awry horror flicks like 'Wolf Creek' (and its sequel), 'Rogue' and 'The Darkness', wields the microphone to narrate the real-life account of a group of backpackers getting lost in the wilderness of the Amazon (in Bolivia). The tale is told from the perspective of Yossi (Daniel Radcliffe), an Israeli explorer hell bent on juicing more out of life than the usual routines. While on a backpacking expedition in South America, he befriends Marcus (Joel Jackson) and his photographer-acquaintance Kevin (Alex Russell), and happens to meet an Austrian gold-digger Karl (Thomas Kretschmann), who suggests a trip deep into the jungles of the Amazon in search of a near-extinct Indian tribe.

Justin Mongo's screenplay offers a slow-burn adventure that takes its own sweet time to peak. The shock value is added on by McLean who has just about mastered the art, by essence of his earlier ventures. Let's talk about the film's shortcomings first: the characters other than Yossi, are unfortunately not fleshed out well enough. Quite a lot is unraveled in the first half hour: the blokes meet, they make merry, and in no time, they're in the middle of an Amazonian voyage and emotional rifts have slowly begun to show. As we'd expect, things don't go according to plan (they never do, do they?) and the gang splits up. While Karl's character is shrouded in mystery, the supposed new friends of Yossi appear half-baked but are saved somewhat by the actors' pretty-decent portrayals.

Now, on to the positives: the film's recall capacity truly lies in Radcliffe's rendering of Yossi (with an accent), and the struggle (infection, desperation, starvation, isolation and of course, survival) he goes through for about three weeks. The hallucinatory episodes provide a little bit of comic relief in between terror-inducing segments. The point is made loud and clear: the jungle definitely isn't an easy place to get by. The obstacles lie in the form of the rainy weather, the unpredictable rapids, fungal/parasitic infection, attacks from wild fauna and low chances of rescue. McLean effectively engineers a scene where Yossi tries to protect an indigenous woman (who's later shown to be a figment of his imagination) - to remind us that the character, even during the most trying of times, hasn't lost his sense of empathy and compassion. This is again reinstated when he decides against killing a turtle for dinner.

'Jungle' assuredly rests on Radcliffe's shoulders almost throughout the entire third act and the 'Harry Potter' star's graph is certainly cresting, owing to a great selection of films - last year's 'Swiss Army Man' & 'Imperium'. Yossi's physical transformation is remarkably perturbing too: a clear indication that the actor's efforts managed to look on-point. The sequence where Yossi and Kevin get separated is adeptly shot: the bumpy ride through the rapids looked to be dangerously unsettling. Music by Johnny Klimek is more befitting a horror film than an adventure drama and at places, seems a bit out-of-sync. Cinematographer Stefan Duscio captures the chaos of the jungle in all its vicious beauty.

McLean and his writer should have utilized their first hour to build stronger, more relatable bonds between the protagonists instead of opting to showcase a rather straight-forward approach. Just look at 'The Lost City of Z', or '127 Hours' and we'll know why these films were able to resonate a lot better than 'Jungle'. A couple of body-horror scenes (as you'd imagine in a Greg McLean film) are bound to make the viewer squirm. However, 'Jungle' simply needed more shocks, more emotion and well-rounded character arcs.

Verdict: A moderately entertaining fare for lovers of survival- drama!