Everything is based on the android version.
This mod replaces the first box with the Holiday Gift box. I replaced the menu and in-game music, various visuals and of course the first box levels. The last level is altered as rockets are not available in this version of the game.

The downloadable zip file contains 2 main folders "MOD" and "ORIGINAL". To install the mod simply replace every file in the installation path "content" directory with the files in the "MOD" folder.

In case you want to revert back to the original version you can simply Verify Integrity of Game Files or replace every file in the "content" directory now with the files in the "ORIGINAL" folder.

For a better experience I suggest (backing up and) deleting your save files and so starting a new game and progressing normally but this is not necessary.

Originally I wanted to write an extensive modding guide however I just learned a couple of days ago that a modding community already exists for this game. They released their own Holiday Gift mod a long time ago and they even created a user friendly level editor.
This Discord community can be found here:
Cut the Rope Home[discord.com]

As for the modding itself, this is how I made the modifications quickly and simply:

• Some of the files are simply replaceable, like video and music files. Also the levels/maps are simple text files in XML format which you can replace or edit.
  
• The rest of the files (mostly the images) are in a special XNB file format.
  
• To pack and unpack XNB files I used a tool called xnbcli[github.com]
  
• The unpacked images are simple PNG files which you can edit with Photoshop or any other image editor.
  
• The repacked XNB files can simply replace the original files.

So there you go, modding the game isn't that difficult after all.

If I update this guide or the Holiday Gift mod, then I'll leave an update comment in the topic below. If you want to get notifications, subscribe to the discussion.
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