It's the ultimate teaser for what will surely be one of the best games of the year. The recently released Uncharted 3 multiplayer beta may well be low on content in terms of actual game assets (only two maps are available, with a third set to be unlocked imminently) but it still offers a wealth of different multiplayer modes and 25 levels' worth of progression, including a large range of weapons, character customisation elements and gameplay-shifting boosters.

Alas, what it doesn't offer is much in the way of hints on what we should expect from the single-player campaign mode, where Naughty Dog really pushes back boundaries with its superb set-pieces and innovative platforming gameplay. In this sense, Naughty Dog's brilliant Uncharted 2 multiplayer beta did at least give us some co-op action that was a fairly close match to the single-player campaign stage based on the same level. Update: The final phase of the beta unlocked this mode. Check out a complete gameplay runthrough in this blog post.

Excited as we are about the new beta, it's safe to say that from a basic technological level, the core rendering elements we see here aren't that far removed from what we saw in Uncharted 2. Then again, short of optimisation efforts and the introduction of new visual effects, it's difficult to see where Naughty Dog could have radically improved its existing tech in the way that it did between the first two games in the series.

As it is, we have been able to pick out a small range of changes and improvements from the slice of gameplay revealed thus far. To begin with, the 2x multi-sampling anti-aliasing has been removed completely. This is a good move on the part of Naughty Dog: the coverage we saw in Uncharted 2 wasn't especially fantastic and by moving to a different solution the developers can free up precious memory and bandwidth. In its place is what appears to be a new form of post-process/screen-space anti-aliasing technique we've not seen before.

It is perhaps a less exhaustive or cheaper form of MLAA and it seems to be pretty good at smoothing off long edges, but it does seem to miss a lot of jaggies we would expect it to pick up on. Coverage is inconsistent, but where it is applied it does a good job, and the technique remains in place on the split-screen and 3D modes, which really push the Uncharted engine to its limits.

Other elements of the image make-up also appear to be refinements of the existing technology. The ambient occlusion was a little lacking in Uncharted 2, essentially radiating outwards on a firm x and y axis, giving a "plus" shaped look. The new effect in Uncharted 3 is significantly more refined. Similarly, the implementation of dynamic shadows looks to have been improved: the shadow cascade seems to be smoother than it was in Uncharted 2, meaning less noticeable transition points between different shadow resolutions as you move further into the scene.

These shots reveal the team's own post-process anti-aliasing solution - note the inconsistency in edge-smoothing coverage. Sony's MLAA technology produces some outstanding results but requires a lot of SPU time. Naughty Dog appears to have developed its own post-process AA technique.

Another element that stands out in the Uncharted 3 multiplayer beta is a revised take on Naughty Dog's wildly innovative dynamic traversal system. This technology was showcased most effectively in Uncharted 2 on the classic train stage, where Drake moves between train carriages travelling at high-speed through the environment. In the beta's Airstrip stage, we see players battling it out as a cargo plane gathers speed for take-off, pursued by multiple vehicles each travelling at a different speed. It's a small hint of the kinds of new gameplay opportunities we hope to see expanded in other multiplayer levels and of course in the main single-player campaign.

While the basic rendering is perhaps best described as a more refined version of what we've already experienced in Uncharted 2, it's clear that Naughty Dog has spent a great deal of time and effort in enabling its engine to run two game instances simultaneously, making this the first PS3 title from the developer to feature a two-player split-screen mode.

At this point, what is very cool is the ability to have two separate PSN accounts logged in simultaneously in what looks like an underlying OS improvement added to a recent firmware (the in-game XMB is utilised here in order to select the secondary account). This is essential bearing in mind the fact that Uncharted 3 multiplayer is geared completely towards customising the player's appearance, load-outs and its own version of Call of Duty's perks. Now two players can progress and level up simultaneously while playing on the same console, even if their accounts are registered to different PSN regions.