This is really good but in real life if the marble was to hit another straight on wouldn't it bounce straight back the way it came? Just a suggestion. :)

@Green_Code, actually, no. All the energy would be transferred to the forward marble and the one doing the hitting would presumably stop. In real life, the only difference would be due to the roll of the first marble. Compare them to, lets say, billiard balls. The one doing the hitting would roll slightly forward. The only ways the hitting marble would reverse is if it had back-spin on it during contact OR if the second marble had more mass than the first (provided no other objects are influencing the system).

@Mik, I downloaded your game, and sends one Error. Class Board, method getGoldMarble(), Line: List<Actor> marbles = getObjects (GoldMarble.class); //incompatible types Solution, chance Actor to GoldMarble. I obviously don't think you made a mistake, I suppose the problem are Greenfoot or Java updates.

@valdes - you are right. This was caused by a change in the Greenfoot API in a newer Greenfoot version. I have fixed the source code now - running the downloaded version should work again now.

@theonlybenjamin, You can Download all book scenarios from https://www.greenfoot.org/book/material/book-scenarios.zip and from that go inside the folder and follow; book-scenarios>chapter13>marbles. You will have other scenarios, too. if you want you can copy the marbles folder to another folder and delete the other scenarios(I think I will keep them to explore more about them).

Why i have been banded for posting anything in discussion I have shared your youtube channel link i.e. ' channel Greenfoot ' and i shared it only for educational purpose and to help ' mik. '(one of the user of greenfoot) It was clearly said that my post will be checked by the administrator within 24 hours, but its more then 24 hrs I was not an illegal spam but till now i m not able to reply in discussion I think the administrator don't follow the rule fairly Plz allow me to post in discussion And also reply that can i share ur channel link or not(I think its not a spam)????

Great addictive and nice looking game! After some hours of play I would definitely appreciate to fall back to a level and not to the very beginning ;)