The "real" save files are stored in www\save. If you have one before the boss, copy it over to this new version and just play through the end. That'll get you the DataCrystal file.
Viewing post in Cruel Serenade 0.3.3 is up! comments
Chapter 2 isn't out yet publicly! Coming soon though. This is just being released first so people have a chance to replay 1 if they want and get a save set up and ready for the release of 2. 1 and 2 will be two distinct, separate games with their own folders, so to transfer some info between them, once you've got both, you'll need to play 1 to the end, take the DataCrystal.js file that shows up in its www directory, and copy it to the www\js\plugins directory for 2. Also keep in mind that you don't have to if you don't want to. 2 will be playable without it, and you'll only be missing out on one scene.