Reusable means that you have some classes, in this case widgets which make up the ui, and you can rearrange them however you want. The login menu is really more a demo of what can be done with it. Another example would be the raycasting scenario, where you can see visually how the ray casting works, but you can use the underlying ray cast system in any scenario. What you may find is that these classes are not visible if you open the scenario in Greenfoot. Just like you need to import the Greenfoot stuff with „import greenfoot.*;“ you need to import my stuff, for example „import com.github.rccookie.greenfoot.game.raycast.*;“. This is certainly a bit longer but normal for java. A package basically describes the folder in which the file is located. That is why you will find exactly that folder structure in my scenarios. Concerning „MyWorld“, that’s because of two things: 1. You don’t have to name your world „MyWorld“, and I never do 2. I am not actually extending World directly, which is why you ain’t see my world class under World. What I actually do is extend a class that is also part of my library which that is extending the World class.

Same on my phone. It’s because the refresh symbol is actually a character from the font, and the font does not seem to be supported on the phone. And the alternative font does not have a character symbol for the refresh char so it shows the classic „no char for that“ char.

@danpost I propably would have used actors at a big cell size, given them a boolean field "reached" defaulted to false and use getNeighbours() on each of them once per click to check for new tiles of the same color next to them. However it is clear to see that that cannot be the case here because the main grid is not in the world grid.

Yeah, anything like that that works with files or ever Formatter does not exist in the JavaScript online conversion. It may be interesting for you to right-Click onto the background of the website, select „Inspect“ and navigate to the console. The warnings are caused by the Greenfoot side itself, but exceptions and System.out.println() calls will show up here