On October 23, 2014, Hitbox announced on their website that a free update to Dustforce, Dustforce DX, was available to all owners of the base game. The DX update added 109 community maps accessible through an in-game console, a new music track by Lifeformed, and support for Steam trading cards. The update also included changes designed to make the game friendlier to newer players. The single tutorial was broken into 3 separate maps, 16 easier levels were added, and the 4 world hubs were consolidated into a single area. The overworld redesign makes it more difficult to reach the harder levels. According to Hitbox developer Woodley Nye, the redesign “helps in two ways: it keeps new players away from levels they aren't ready for yet, and it serves as a teaching tool for more advanced techniques that are required in the tougher levels.”
Source: Wikipedia, "Dustforce", available under the CC-BY-SA License.