If you dont have internet and get BL on a disc or something from a friend any key will work but when you have internet it will ask you for the code. I think its good that people without internet can still play blockland without brick limit (Like at school :D)
When you start blockland, with the full version. You see in console Authentication: Success. Now if you didn't have internet, how could it check that? I think it wouldn't work, but i haven't tried it myself.
I mite check the .dat file that it makes when the demo turns into Retail.
