These sounds from freesound.org and licensed via Creative Commons licenses.
The details of each license along with source for each sound is listed below.
All sounds have been converted from .wav to .webm for space.

alarm.webm
  https://freesound.org/people/ZyryTSounds/sounds/219244/
  http://creativecommons.org/publicdomain/zero/1.0/
  modifications: shortened to first second

amy/
  http://www.freesound.org/people/Timbre/sounds/83033/
  https://creativecommons.org/licenses/by-nc/3.0/
  modifications: sound cut into separate files

percussion_hit.webm
  https://freesound.org/people/Stumber/sounds/207863/
  https://creativecommons.org/publicdomain/zero/1.0/

power_up.webm
  https://freesound.org/people/GameAudio/sounds/220173/
  https://creativecommons.org/publicdomain/zero/1.0/

sonar.webm
  https://freesound.org/people/NoiseCollector/sounds/6164/
  https://creativecommons.org/licenses/by/3.0/

water_drop.webm
  https://freesound.org/people/paespedro/sounds/174718/
  https://creativecommons.org/publicdomain/zero/1.0/