This way, in Manic Digger you start the game with a single character on a deserted island that's generated in a random way while you move on it, and that you can 'decompose' square by square. With the left click you can take away any block of the scenario (sand, earth, wood, stone...) and with the right click you can place a new block.
In the present version of the game, the inventory is always full of each type of blocks in a similar way as it happens in the creative version of Minecraft. So, you will not have to worry about gathering materials when you start to create your houses, buildings, monuments and other structures.
Another benefit you won't find in Manic Digger is the presence of enemy creatures or characters controlled by the artificial intelligence. Even so, you will have the possibility to play on servers with friends and even apply different mods and texture patches.
Manic Digger is a very interesting alternative for Minecraft. Of course, it doesn't offer the same quantity or quality of benefits, but a quite similar general experience in a completely free way.