What started out as a lark with LEGO Star Wars has turned into a powerhouse franchise for Traveller's Tales. The UK-based developer has more or less single-handedly made LEGO video games cool and in-demand for players of all ages. As a result, we couldn't resist taking a peek at LEGO Batman 2: DC Super Heroes at E3 2012. Sure, it comes out this month, but who ever went wrong with LEGO?

A sequel to 2008's LEGO Batman, LEGO Batman 2 expands on the original both in character selection and level design. Like the first, LEGO Batman 2 is not based on a pre-existing story or movie. Instead it eschews the known for an original adventure. As it happens, Joker decides he needs an assist, so the crazed crazy man teams up with Lex Luthor to rain havoc upon Gotham. Because Luthor's involved, Superman decides to lend a hand, and the Justice League is eventually called in to help.

By using an original story rather than a pre-existing plot, it gave the developers freedom to create specific story elements for each character. We're told that the adventure has you exploring multiple locations within Gotham City as well as visiting Metropolis and sneaking a peek inside LexCorp. Gotham itself is broken up into three main islands, though you aren't limited to any specific section of the city. Instead, it's an open world.

You are free to explore Gotham at your will, including going to the top of Wayne Tower or heading on over to Arkham Asylum. Because of the size of the city and its open-world nature, the developers told us that LEGO Batman 2 won't be able to feature on-line co-op. Co-op will be limited to split-screen only. Individual levels are larger than previously seen in LEGO games, so a mid-level saving system has been implemented.

The sheer size of Gotham presents plenty of opportunities for the various characters to show off their powers. For example, Superman can fly around at will. You can use him to scale the heights of Gotham and get the lay of the land. Flash can run (and fight) at super speed. Every hero will attack the landscape a bit differently. Green Lantern can interact with translucent green LEGOs, while Cyborg gets to use all the magnetic LEGOs.

Even with the variety, Traveller's Tales hasn't lost sight of the LEGO humor. For example, Superman is invulnerable to most damage, but if you fly toward the ground too quickly, he'll take a header into the pavement and be stunned for a second until he gets up and shakes himself off.

Aside from the open-world nature of the game, the biggest change being made to the franchise with LEGO Batman 2 is the addition of actual voices. The traditional LEGO mumblecore is out, and real, live dialogue is in. We didn't hear any of this in action on the floor at E3 2012, but it promises to be an interesting change. To be honest, we're not entirely sure how to feel about this one, as the ambiguity of the dialogue has always been part of the series' charm. We'll have to see how it pans out once we get a final copy for review.

Vehicles are a part of LEGO Batman 2, with specific choices for land, sea and air. You'll be able to spawn in vehicles via remote terminals at pre-selected points throughout Gotham. Yes, the Batmobile is here.

Some of the confirmed characters we saw in the demo include Bane, Brainiac, General Zod, Harley Quinn, Harvey Dent, Hush, Killer Moth, Mr. Freeze, the Penguin, Poison Ivy, Sinestro and Riddler. This is in addition to those previously mentioned.

Just like the first game, the Batcave serves as the primary hub world. This is also where you can create your custom superheroes. There are 10 custom character slots, split across five different templates. For example, there are two flying characters, but as long as you stick to the templates, you are free to mix and match powers. It'll be interesting to see how creative players can get.

Over on the handheld front, LEGO Batman 2 is a little different than on the PC and consoles. Because of the smaller game size, the handhelds do not feature an open world. They do, however, have local co-op via Wi-Fi. The handhelds also feature additional exclusive characters, such as Green Arrow and Superboy, which you won't see on the console versions. Finally, the handhelds have a specific Justice League mode that has you playing through a series of levels as Justice League characters.

It may be a departure from the existing formula, but it's nice to see Traveller's Tales trying new things with the LEGO franchise. If the series is going to maintain its popularity, it has to evolve, and it sounds like Traveller's Tales is doing just that. Now, if only they'd get around to producing LEGO Doctor Who ….