Thanks for trying it out! In chemistry life every combination of particles had a different radius where they interacted, thats why you don't see those shells anymore. I'll add it as an option in the next version. 

Very nice, especially the DNA mechanic is cool. 

Hi, thanks for the comment. I can't find a private message tool either but you can email me  here : buuddhaman@gmail.com . 

The .zip file has the Java Runtime Environment bundled with it, its for people who don't have Java installed. If you have Java you can also run the .jar file. 

You can move the camera with W A S D and zoom with Z and X. This way you can place the playfield area in the center. 

Hi, you need to drag and drop some particles into the square above the table first. Then press the button and it will produce a reaction table.