I think a single player adventure story is exactly what Blockland needs to get its ass in gear to compete with other building sandbox games. Let's say this single player adventure could be similar to the official Lego Island's layout. We could have a small island village map complete with it's own goals, quests, unlockables, NPCs, etc. I actually have a great example, there is a fanmade game called Lego Island 3 which uses almost the same tools as torque and the entire map is scripted to include quests, trigger events, etc.
Take the concept from one of these examples and turn it into your own adventureI'll add more information as I go along with this.