If you download from the Elementist Web site, there are two zip archives.
The executable code is in Elementistav0_4.zip.
The other file, Tutorial.zip, has two .wld files that should be placed
into Elementist/Data/Tutorial. 

If you download from the IMGD-3000 Final Projects page, there is only one zip archive,
ElementistGame.zip, which contains all you need, and in all the right places.

Commands can be entered in the console, which is brought up using the tilde/accent key.
To Run the game, at the console, type "load water3" for
the tech demo, and "load Elementist" to see the basic level design.

Keys:
WASD and mouse to move and look around, same as the C4 demo

home row number keys 1 through 0: change elements
1 - air
2 - earth
3 - fire
4 - water
5 - fireball (air and fire)
6 - ice (air and water)
7 - lava (fire and earth)
8 - quicksand (water and earth)
9 - sandstorm (air and earth)
0 - steam (fire and water)

Tips:

You may need to move around a little bit to get each object to highlight
with the appropriate color.  Usually you may need to point a little further
up than you would expect.  The rocks in the demo are laid out in numerical
order in a clockwise fashion; that is, the first rock to your right reacts
to earth, and the furthest rock in the back reacts to steam.