The game was written in Sprite Kit, and the source is published both as a marketing tool to promote my other games, plus help anyone who might be interesting in learning Sprite Kit or writing his/her own Piano Tiles game.
High level structure is as below and shouldn't be too hard to understand.
(1) What's the difference between the published game and source available for download?
The only difference is the launch image been replaced by simple image as below.
(2) I can't find the link to download the code?
After you clicked on the link (shown far, far below...), as shown highlighted in red below, click on the icon with downward pointing arrow in the upper middle of the screen to download the file.
(3) Under what license was the code released with?
The only condition for downloading the source will be to download all my games as below and play everyone of them for a few times, simple as that! Optionally, please leave a positive comment for me!
(4) I found a bug, what next?
Well done, thanks for that! Please post it as comment below or email me, and I will try to fix it in the next release.
(5) I don't understand why you do xxx this way....
Please post any question or suggestion or further improvements ideas below and I will try to explain it here if possible.
(6) Cut the crap, where is the link?
Alright, assuming you did follow my conditions above and downloaded all my other games, here it is , enjoy!
For those who prefer github, it's also available here