For a videogame based on an upcoming blockbuster movie, we really know an awful lot more about Ubisoft's licensed product than we do James Cameron's film. What we hadn't experienced though was the game and movie's major selling point of being viewable in 3D and we got a hands and eyes on with that at gamescom.

Our first impressions were broadly positive. Avatar the game uses the same kind of polarising 3D technology that you may already have experienced in the cinema. The overall effect in Avatar is spectacular. This is a luscious, green and vivid world that switches to a luminescent jungle at night. The atmosphere is claustrophobic at times and you will almost certainly start bobbing and weaving in your chair as you look to dodge incoming tree branches. It works really well with the combat too, giving you a superb sense of depth and distance against your enemies to timing leaps and dodges.

The core shooting mechanics are also very well put together although there are some control choices that we will get into shortly. When playing as the human forces you're in a familiar third-person shooter scenario. There's no cover system from what we could tell, but you can carry up to four weapons, jump into vehicles or mechs and generally have a rollicking great time. Your sole task in the game is to destroy the wildlife and generally cause mayhem. At certain points in the game though you will be given the chance to switch sides and play as he local Na'vi.

The Na'vi are largely melee-based in their combat although you can use a bow and arrow with great effect. Their other weapons include a heavy staff and twin hand blades, each of which has its own benefits and weaknesses (speed versus strength versus range). The control setup for both races is identical with combat on the right trigger or R2, evade on the left trigger or L2 and weapon selection on the D-pad. The Na'vi's evasion leaps are particularly acrobatic with their ten-foot tall frames actually being incredibly agile and light.

But the controls show up some of the compromises that have been made in this game. By having both races use the same control layout, neither is utterly satisfying to use. Both are quite functional and simple to use, but sometimes a little complexity adds depth to the experience. The shooting combat is very light and untroubling. We never really felt in any danger behind the guns of the humans even if the world did throw some surprises at us. The Na'vi combat could also have done with some complexity. With all their melee attacks on one button and seemingly on a couple of animations per weapon you never really feel as powerful and skilful a fighter as you clearly should. The bigger picture of what has been achieved with Avatar remains impressive, but the core mechanics of the game being what they are means that it is unlikely to challenge any of the big gaming names coming out later this year.