I liked a couple elements of it. Since it is based on PowderToy engine, every feature it has should be able to be ported to TPT. This includes a ball that bounces (yes it's a moving solid, but the implementation in PG only requires that it can detect other objects to bounce off of, and not that other objects can detect it and respond to it, so that should be fairly easy to make in TPT). Other feature is called Bubble. Hold down the mouse button and the circle gets larger and larger and it too behaves as a moving solid, but again it doesn't require that anything else interact with it, just that it can respond to the presense of everything else, namely by turning into the same material as the first object it touches (it's a form of of CLNE it seems) and it can blow in the wind. Yeah that would be some awesome things to put in TPT. The TPT developers should really look into copying some of the features of PG to put in TPT.

Odd thing is TPT's oldest version is called Powder Game. I saw this on Internet Archive's archived page from your old website from 2009. That's why I was thinking they were the same.

Also just a question, what kind of lockout is that guy using on his online Powder Game? I went to my browser and did "save page as" and selected "complete web page" (which makes it download all the dependencies such as image files and jar files and javascript files as well as of course the html file). I then doubleclicked the html file and the whole page loaded fine EXCEPT FOR the Powder Game app itself. So I'm wondering just what kind of lockout he programmed into his game that FORCES it to not work when being played from any other location than his website.

Oh, and if moving solids don't work in TPT, why does stickman and fighter work?
And how do the bubbles from the SOAP element work?
Any time 2 or more particles have a direct physical link that allows one to move the other but without physical contact, you have a moving solid. So that means that TPT already has 3 types of moving solids (stkm and stkm2, fighter, and bubbles from soap). So I don't understand the reluctance to make rectangular moving solids. I never really understood that.

Actually it would require only a very simple addition to the TPT engine to make moving solids a common thing in TPT. Just have one more array (we already have temp and stuff). The new array would be the OBJECT array. Each time you drew on screen like CTRL+DRAW to get a rectangle, and then released the mouse button to complete that object, it would assign ALL particles in that object a single value. The fact that all particles in a given object share a single common value that defines that object would make this real easy. Then your code that keeps the particles moving in a way that makes the solid be have in a way with physics should be fairly simple. Each particle would know the location of its neighbors which also have the same object value. Having neighbors which have different object values would indicate a collision between 2 different objects. This would then result in a force being applied that would stop the motion of the objects so they didn't attempt to pass through each other. If the force was unballanced then the object would begin to rotate about its center of gravity. The location of the COG is simple to calculate as all it is is the average of the position coordinates for each of the particles in the object, and of course since all the particles in a given object have the same object ID number, that means finding all the particles to get their locations is a simple piece of code to write.