I beat the game in 15 minutes or so. Was that really it? :S
Now I start making maps and play until I get bored right?

LAST BOSS IS A FREAKING DRAGON... That's too easy to kill.

You pre odered and got access to the very early alpha. Theres not much content yet and if you read the latest blog post you wouldn't ask.

The game consists of a voxel and map editor, along with an arcade mode and a sample world ("Adventure Mode") which shows some of the things you can do with the current editor.

See here

Ah, thanks. Didn't notice it. Thank you!