Sounds
------

Mito551 (sounds) (CC BY-SA 3.0):
  grass.*.ogg
  gravel.*.ogg
  hard.*.ogg
  sand.*.ogg
  wood.*.ogg
  dirt.*.ogg
  glass.*.ogg

Ottomaani138 - CC0
  Metal.*.ogg https://www.freesound.org/people/Ottomaani138/sounds/232692/

Ryding (CC0 1.0):
  snow.*.ogg http://freesound.org/people/Ryding/sounds/94337/

Textures unless listed are by Nathan Salapat (CC By-SA 3.0)

levels_wood_0 Public Domain from https://opengameart.org/content/wall-grass-rock-stone-wood-and-dirt-480?page=1
  levels_scifi_6 adapted from Majestical textures by Adam Foster, Randy Reddig, and Robert Yang (CC By-SA 4.0 Intl)

cc0textures.com licensed CC0
  levels_brick_2.png
  levels_brick_3.png
  levels_brick_4.png
  levels_brick_5.png
  levels_dirt_1.png
  levels_gravel_1.png
  levels_marble_0.png
  levels_marble_1.png
  levels_marble_2.png
  levels_metal_0.png
  levels_metal_1.png
  levels_metal_2.png
  levels_metal_3.png
  levels_scifi_15.png
  levels_snow_1.png
  levels_stone_3.png
  levels_thatch_0.png
  levels_wood_7.png
  levels_wood_8.png

Carlotta4th http://www.minecraftforum.net/topic/158542-16x-32x12-precisely-portal-and-modified-portal/#Index
  levels_tree_1-5_top.png
  levels_tree_1-5_side.png

Summerfields 32x http://cuddlewoozle.github.io/SummerFields/
  levels_leaves_0-6.png
  levels_dirt_2.png

jojo-ojoj CCA 3.0 https://www.deviantart.com/jojo-ojoj
  levels_brick_6.png
  levels_brick_7.png
  levels_brick_8.png
  levels_metal_4.png
  levels_metal_5.png
  levels_metal_6.png
  levels_metal_7.png
  levels_metal_8.png
  levels_metal_9.png
  levels_metal_10.png
  levels_metal_11.png
  levels_metal_12.png
  levels_metal_13.png
  levels_metal_14.png
  levels_sand_5.png
  levels_sand_6.png
  levels_sand_7.png
  levels_scifi_16.png
  levels_stone_4.png
  levels_stone_5.png

celeron55, Perttu Ahola: CC By-sa 3.0 MTCORE32px
  levels_slate_tile.png
  levels_tree_11_side.png
  levels_tree_11_top.png
  levels_tree_12_side.png
  levels_tree_12_top.png
  levels_tree_13_side.png
  levels_tree_13_top.png
  levels_tree_14_side.png
  levels_tree_14_top.png
  levels_tree_15_side.png
  levels_tree_15_top.png
  levels_tree_16_side.png
  levels_tree_16_top.png
  levels_tree_17_side.png
  levels_tree_17_top.png
  levels_tree_18_side.png
  levels_tree_18_top.png
  levels_tree_19_side.png
  levels_tree_19_top.png
  levels_tree_20_side.png
  levels_tree_20_top.png
  levels_tree_21_side.png
  levels_tree_21_top.png
  levels_tree_22_side.png
  levels_tree_22_top.png
  levels_tree_23_side.png
  levels_tree_23_top.png
  levels_tree_24_side.png
  levels_tree_24_top.png
  levels_tree_25_side.png
  levels_tree_25_top.png
  levels_tree_26_side.png
  levels_tree_26_top.png
  levels_leaves_7.png
  levels_leaves_8.png
  levels_leaves_9.png
  levels_leaves_10.png
  levels_leaves_11.png
  levels_leaves_12.png
  levels_leaves_13.png
  levels_leaves_14.png
  levels_leaves_15.png
  levels_leaves_16.png
  levels_leaves_17.png
  levels_leaves_18.png
  levels_leaves_19.png

Luke.RUSTLTD CC0
https://opengameart.org/content/3-crate-textures-w-bump-normal
  levels_crate_1.png
  levels_crate_2.png
  levels_crate_3.png

Cpt_Flash CC0
https://opengameart.org/content/2d-wooden-box
  levels_crate_4.png

PilzAdam, CC BY-SA 3.0
  levels_lava_crust_animated.png

texturelib.com
  levels_brick_10.png
  levels_brick_11.png
  levels_concrete_4.png
