Thanks for playing here! I still need to balance the challenge level and other things in this game, I'm really eager to do soon! :)
Oh, yes, the voices were all recorded by myself! :) Actually, I just used an old iPad 2 (internal microphone) with RecTools, changed the pitch using SoundForge and processed the pitched sounds using FL Studio (eq, reverb and some lo-fi plugins). I really like tampering with audio. :P