Manic Digger, Free Minecraft Clone
Manic Digger is probably the most popular and functional Minecraft clone currently available. I downloaded it and playtested it to see if it was even remotely close to providing the same sort of experience that Minecraft does. (Spoiler: It's not.)
At first, Manic Digger appears to be a very sold Minecraft clone. The block types are very similar to those in Minecraft and so is their appearance, but that unfortunately, is where similarities end fairly abruptly.
Crafting is awkward to say the least. At first I thought that it wasn't even possible, but I realized that when I pressed 'B' that opened a window with a bunch of block types in it. A blue dotted block in this array serves as a crafting table. By placing other block types on top of the crafting table, you can craft new block types. For instance, putting a block of sand on the crafting table then looking at the crafting table and pressing C creates a block of glass. In theory, pressing L should take the glass, but it didn't seem to work.
On the Manic Digger Wiki there's a comprehensive list of what Minecraft features are not available at the time of writing. I'll put it here to save you the bother of going to find it.
Linux and Mac support. Web browser applet.
Day and night cycle
Tools and weapons
Map generator - cliffs.
Custom servers and mapping tools
It's fast. Blocks disintegrate the
moment you hit them, which saves you the tedium of sitting there for
ages watching your pickaxe go up and down, up and down until you
finally have some stone. Manic Digger really does allow you to dig in
a Manic fashion, so at least it lives up to its name. It's also
pretty amusing if you simply want to make things out of blocks and
never want the sun to set on your creations. Not everyone is a fan of
the day / night cycle and if they leave it out of the final version
entirely, that might actually be quite a bonus for them. On the
downside however, if you dig your way down to the bottom layer of
what may or may not be lava, there's no obvious way of getting out.
You don't take damage, but you can't place blocks on it and so you're
doomed to a life of paddling in murky pink waters.(Enabling free move will probably get you out of the sticky situation though.)
Pressing F2 increases your move speed to 10x the normal, allowing you to practically fly about the map.
Pressing F3 enables 'free move' which means literal flying. (Unfortunately, turning free move off appears to make you fall through the world as if it were made of butter and you are a hot knife.)
The blatantness of the clone. I know that 'clone' is a word that means 'precise copy', but the world really doesn't need a clone, what we probably could do with however is a game that took the base elements of what makes Minecraft great (the fully destructible world, the almost unlimited crafting options and block types) and took it in an entirely new direction. Manic Digger copies Minecraft right down to the useless book cases, which is a little bit dissapointing, especially as much of the functionalty that makes Minecraft actually worth playing is missing from Manic Digger.