A couple months ago I started to play Minecraft. To play go to http://minecraft.net/. Minecraft is a java game that you build and destroy 1X1X1 blocks which you use to fight the zombies, skeletons, and spiders which are there to kill you. There are 4 modes: Peaceful, Easy, Normal, Hard.
Peaceful mode means there are no zombies, skeletons, or spiders that are there in other modes to kill you. You an build and destroy blocks, but you can still be harmed. For example: if you fall from a great height you will lose health which in turn will kill you if you run out, If you fall into fire or lava you can burn to death, if you fall from a great height into shallow water you will lose health. The best part about Peaceful mode is that you can regain health after a while.
Easy, Normal, and Hard mode has zombies, skeletons, and spiders that are there to kill you. The harder the mode is the easier it is to die. When you go on to the easy, normal, and hard modes you do not gain health back over time.
There are different types of blocks: Stone, Ground, Coal, Gold, Iron, Wood, Diamond, Leaves, and Sand.
There are 4 different types of gameplay modes: Survival, Creative, Indev, and Infdev. Survival and Creative are free so you do not need to buy the game, while Indev and Infdev are for people who have purchased the alpha and want to try the latest development version.
Overall its a great game. I have been playing it non-stop.