Starcraft

I want to download starcraft, and all of them are .sit files so I downloaded a stuffit expander, and it opens the file but the game itself isn't working and says classic environment dosnt work or something.

Sounds like you are downloading an older version (one that isn't universal binary) and you have an intel based processor. Basically, you're trying to run a OS9 in a version of OSX that can't emulate OS9. See if you can find a Universal Binary version or a patch to make your version universal binary.