Sound effects

[LeilaDavis]

Add sound effects:

• [x] when failing a level
• [ ] when clicking on buttons
• [x] when train goes over a function track successfully
• [x] when level is completed
• [x] when picking up a frog
• [x] when level starts e.g. train whistle/horn

Probably won't have time for this.

[LeilaDavis]

Files found, need to add to scenes

[LeilaDavis]

explosion sound: https://freesound.org/s/540091/ button press: https://freesound.org/s/658266/ train reached track successfully: https://freesound.org/s/511484/ level complete: https://freesound.org/s/456966/ when a frog is collected: https://freesound.org/s/536759/ train whistle when level starts: https://freesound.org/s/162803/

[LeilaDavis]

thanks josh for adding them to the game