You said it's free.
The license type is marked as Shareware which means Trial version + Purchase.
You need to pay
The game is full of possibilities to create whatever you like, beginning from buildings and ending with computers. I like it.
To my mind the game is dull. A lot of time is spent on digging and exploring, which is sometimes very boring. This is not my game type, though the idea behind it is quite original.
I didn't like the creative mode, as there is no risks and you do not have to fight for your survival. Yup, you can do whatever you want in this mode, but you have no objective other than to create. This is fun at first, but may become boring.
The survival mode is the most interesting one in the game. Yet you might like other modes, especially if you want to have a relaxing game. Minecraft is worth trying.
This survival game has an interesting realization – it is square. Animals, the hero, plants – everything is square and this gives you an unusual feel. The game is fun and lets your imagination work. You can create your home, mines, etc. But, as any game, it has its target public and this one is not for me. I have had enough in half an hour, though I enjoyed the idea of a square world.