After making your objects you must move them over to the game world.
1. New Object Placements
Right-click on your main character object and select the top option e.g. 'new Sheep()'.
Drag your mouse to the world and click to drop it.
Complete the following actions:
Place 1 main character object.
Place 5 collectible objects.
Place 2 enemy objects.
2. Save the World
Once you have populated your world with objects then right-click anywhere on the background and select 'Save the World'.
This saves the positions of each object so that it won't reset every time you start a new game.