I was so excited about the new update, I've been waiting for it! But will I lose all my old save and will I have to start all from scratch all over again? I used the gift code you instructed for the old players but wouldn't have a way to replace some file so I didn't miss all my previous progress and continue where I stopped?

Hello!

Your old save file from version 1.4 will definitely not work on the latest version. So there's no way to transfer them. However, from now on, you should be able to carry over your save files with each new update.

So yes you need to start a new game on the latest version. You can use the  earlybird password to unlock the previous content though! :)