You'd need to upgrade to the premium version, to remove the restrictions imposed by the demo version.
Chat with our AI personalities
No
The PC Demo lasts 5 in-game days (1 hour 20 mins) and the PC full version lasts forever
You can play the Minecraft Beta demo by finding the PC Gamer demo on their website. In order to play the full game though, you will need to purchase it from the Minecraft website.
No, Minecraft, the full version, is not free. It costs $26.95 US dollars. However, they do offer a demo version for the PC, and classic (which isn't too much like the full game, demo is more like the full game).
Minecraft for the PC costs 26.95.