In the Trials games players can create their own tracks in the game's track editor, allowing other players to try them out and test their skills on each-others creations.
PneumaticBog484 has actually created a Minecraft-style game, Trialscraft, within the Trials Fusion editor. It allows you to walk around placing and picking up blocks, just as you would in the real Minecraft. Incredible.
You can watch the game in the video below. And you should definitely check out PneumaticBog484's YouTube channel for some more of his creations - he's made a first-person shooter, as well as procedurally generated tracks. Thanks, Kotaku.