The Behemoth teased us with a PAX reveal of Battleblock Theater's level editor, and the Castle Crashers developer didn't disappoint. There's a full-featured level editor included with the game, and it's the same one the designers have been using to make their own levels, controller and all.
Every type of block in the game is available to be placed by you within the editor, and you can color them however you like. Each level obviously needs an entrance and an exit, but what happens in between is up to you. You can choose any of the game's modes (and can even combine some of them), lay out resources to collect, and even build little Rube Goldberg devices with the various available components. One example shown to us used boulders and timed pneumatic devices pushing them onto switches, which created a sort of timed trap for characters to navigate. Extra creative users will come up with even more complex and varied setups, we suspect.
Even if you're not looking to create levels, The Behemoth has you covered. To start with, users will be able to share and send levels to each other. There's a "Level Lobby" in the game's main menu, where you can download playlists of created levels, see feeds for highest played and Behemoth favorites, and play and rate all of the levels you can find. Levels do need to be downloaded locally to be played, but they're tiny, so bandwidth and storage shouldn't be a problem.
We'll have to see how the level sharing system actually works post-launch to see how prominent it becomes (Castle Crashers, of course, suffered from connectivity problems during its release, which made playing multiplayer tougher than it should have been). But The Behemoth has created a powerful editor here, and it'll be fascinating, as with most user-generated content systems, to see what players can do with it.