Oh my, thank you so much for your comment!
Sound design is something I really wanted to add but sadly there was not really any time left to create the audio that I would have wanted. Maybe in a future update? ;-)
Yeah, I wanted to make sure that the player can concentrate on the puzzle piece's shapes in the first level without being confused by different pieces, which worked great for other players, but that might have just been the wrong way around for you :P Everybody is different!
Well whatever, we're really glad you enjoyed the game!