Martin Sofiedal, the director of short fan film Uncharted: Ambushed, has been offered a glimpse of Uncharted 4: A Thief's End behind closed doors at developers Naughty Dog.

The next Uncharted adventure is being kept tightly under wraps but the studio was impressed by Sofiedal's work and rewarded his fandom with a sneak peek at the next and possibly final game in the series.

Martin reported what he saw to Norwegian site (via PS Mania) saying: "I got to see a few seconds of the opening scene, which is still under development, but already looking incredible.

"I got to see some pretty raw stuff from the new game, including drawings of planned action sequences and how all the characters look like now with upgraded graphics. It was almost scary to see Sully as an almost living person."

Martin said the graphical step up between this and the last game on PlayStation 3 was like the difference between a PS2 title and a Pixar movie.

He said: "They showed some tests where Drake was going through a bit of tall grass and how every straw reacted to his movements while also responding to the wind. It was crazy. I've never seen anything like it."

Only two trailers have been released for A Thief's End since it was first announced at last year's Spike TV Video Game Awards. No gameplay footage has been shown yet but some concept art did reveal a few possible locations for the globe-trotting adventure.

Watch a trailer for Uncharted 4: A Thief's End below. The game will be released in 2015.