Sounds from Kenney (https://kenney.nl), CC0 1.0: public domain, no
credit needed, but here it is.

  Impact Sounds: https://kenney.nl/assets/impact-sounds
  Interface Sounds: https://kenney.nl/assets/interface-sounds
  RPG Audio: https://kenney.nl/assets/rpg-audio

Sounds from Freesound (https://freesound.org), all CC0 1.0: public
domain, no credit needed, but here it is. Cut, levelled and looped for
Earth Two by tools/sounds/fetch.py.

  wind: "Looping Gentle Wind Ambience on an Open Desert Plain" by dhallcomposer: https://freesound.org/s/697217/
  storm: "Sandstorm Looping" by gbayles: https://freesound.org/s/632771/
  hull_hum: "control_room.wav" by Diboz: https://freesound.org/s/211683/
  dome_air: "AC Unit, Interior Exhaust Close Perspective 02" by HECKFRICKER: https://freesound.org/s/753275/
  market: "Farmer's Market Chatter RX" by greysound: https://freesound.org/s/769034/
  fountain: "Ambiance_Fountain_Small_Loop_Stereo.wav" by Nox_Sound: https://freesound.org/s/676173/
  generator: "Scifi_Generator_Lp" by Euphrosyyn: https://freesound.org/s/452768/
  fans: "Industrial Factory/Fans Loop" by IanStarGem: https://freesound.org/s/271096/
  tyres: "tire_rolling_1.wav" by mhad: https://freesound.org/s/390798/
  engine_bike: "Motorbike Idling.wav" by lmbubec: https://freesound.org/s/119455/
  engine_trike: "Quad Bike_ATV Engine.wav" by Alex_hears_things: https://freesound.org/s/379915/
  engine_buggy: "Synth Car Engine Loop 1_1" by Joao_Janz: https://freesound.org/s/482664/
  engine_rover: "Electric Scooter Loop.WAV" by pkri: https://freesound.org/s/587511/
  engine_truck: "Diesel Truck Idling Front.wav" by ibirdfilm: https://freesound.org/s/128160/
  step_grating: "Footsteps On Metal" by IENBA: https://freesound.org/s/834029/
  land_loose: "Human jumping down to gravel w/ impact" by DeqstersLab: https://freesound.org/s/819656/
  slide: "Boots Gravel Feet Slide 1_5" by Joao_Janz: https://freesound.org/s/504383/
  whoosh: "Short Whoosh, 13x" by Kinoton: https://freesound.org/s/427979/
  skid: "auto car or van stop brake skid gravel short" by kyles: https://freesound.org/s/637161/
