People use the argument of 'well minecraft was a rip off of another game', but that just makes them look silly. Sometimes it feels as if i'm part of some secret society, "people who actually learn about what they're talking about before opening our big mouth".
In this case:
http://www.minecraftwiki.net/wiki/Infiniminer
For a little more detail, I found a good blog entry talking about it:
http://blog.hardcoregaming101.net/2010/10/all-matter-is-made-up-of-large-cubes.html
As you can see, minecraft is quite different to the game it 'ripped off'.
-infiniminer was about gathering ores for your team, in a competative multiplayer game. You mine out blocks and return them to give your team points. Highest score at the end wins the round. (You can go singleplayer, but it's just multiplayer with no people so there's really no point)
-minecraft is about building stuff in a sandbox game, with the option for resource gathering and crafting, with enemies that appear in the darkness to antagonise your efforts. Creative mode removes the threat posed by enemies, and the resource gathering requirements leaving it as a pure sandbox building game. Both multiplayer and singleplayer modes.
-both minecraft and infiniminer used blocks
-both minecraft and infiniminer had proceedurally generated levels
and here's a good clincher:
-minecraft was made after infiniminer's discontinuation.
(meaning it wasn't trying to leech off a current successful game like certain others...)
see how minecrafted compared to infiniminer is different from what fortresscraft did when compared to minecraft?
-all three: block based, with procedurally generated worlds.
-infinimier: team and class based competative resource mining game
-minecraft: sandbox freebuild game / sandbox survival resource gathering and construction game
-fortresscraft: sandbox freebuild game
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Also, I think it's pretty obvious to everyone here, but i'll say it anyway: Cloning a game and removing most of it's newest features does not make the game no longer a clone...