Hi guys,
right, the videos don't have much gameplay - they're more of a tech demo. The next step is adding real gameplay. My vision of the final game is the following:
At the beginning, you are a weak hero abandoned in a huge fantasy world full of monsters and mystery. You are so weak that you can't fight big monsters or dare to explore dark dungeons yet.
So you need to improve your equipment first by killing smaller enemies and crafting some primitive leather armor and wooden weapons or things like that.

I dont't want a complex crafting system and there will be no mining and digging. You also can't build stuff.
Once you are more powerful you can kill bigger monsters and explore more dangerous areas, and so on. I think I'm gonna leave out experience points and skill advancement and keep everything equipment-based.
Additionally, I'd like to add randomly generated quests a la "Kill that huge monster over there" or "Find the treasure hidden down there". I'd also like to fill the world with random NPC's giving you quests or selling stuff.
Finally, due to it's procedural nature, the game should be open-ended and you can become mightier and mightier and explore more and more parts of the Cube World.
So that's my vision for Cube World. I hope I can realize it.

I appreciate any comments and criticism.
@roguelikemonkey: The maximum depth is 128 voxels.