Sadly, this project of mine is coming to an end. I doubt I will add any more content, because I moved on to other projects.

Therefore, I decided to publish the original .blend file. If you want to open this file, you must use free software, which you can download here
The version I used was 2.75a, but it will probably work in other version too.

The zip file also contains textures and sound files. Feel free to check out the code, change anything you want and write comments about how bad the code is.

I hope this will possibly help someone.

Enjoy!