medkit_use.wav (original name heal.ogg) and
shoot.wav (original name shot2.ogg):
  from http://opengameart.org/content/spell-sounds-starter-pack
  by p0ss
  licensed on
    CC-BY-SA 3.0
    GPL 3.0
    GPL 2.0
  or above versions of these.

  Somewhat retouched by Michalis Kamburelis, using Audacity.

footsteps_grass:
player_drowning:
player_swimming_change:
player_swimming:
  from http://www.flashkit.com/soundfx/
  (unfortunately do not remember exact URL, I used this sound in castle1 game)
  public domain