all used textures are CC0, some normalmaps are from the submitterers, the rest is self-made out of the textures

brick_grey.png
brick_red.png
made out of http://opengameart.org/content/seamless-brick-textures, by athile


earth-to-x.png
based on image from http://www.burningwell.org

earth.jpg
earth_2.jpg
earth_down.png
earth_top.png
based on images from http://opengameart.org/content/seamless-2, by arikel

glass.png
#selfmade

grass.jpg
grass_2.jpg
grass_end.png
based on http://opengameart.org/content/synthetic-grass-texture-pack, by para

metal_02.png
metal_03.png
based on http://opengameart.org/content/free-tilling-texture-pack-28
and http://opengameart.org/content/free-tiling-textures-42, both by yughues

metal_box.png
from http://opengameart.org/content/tilling-textures-pack-04, by yughues

metal_cross_dots.png
metal_dot_small.png
metal_dots.png
selfmade out of stuff from yughues

q-block.png
#selfmade

stone1.png
stone2.png
http://opengameart.org/content/free-tilling-textures-41,  by yughues

stone_greenish.png
http://opengameart.org/content/tilling-texture-pack-13,  by yughues

stonetiles_00*
http://opengameart.org/content/pietextureset, by Spiney

wood2.png
wood3.png
based on images from http://www.burningwell.org

wood4.jpg
wood5.jpg
http://opengameart.org/content/5-wood-textures, by Luke.RUSTLTD
wood_boxes.png
http://opengameart.org/content/3-crate-textures-w-bump-normal,  by Luke.RUSTLTD