@EduandErnst, when I said 'Try drawing ... " in the last comment, I meant as an experiment to see how it works -- not to change the way the scrolling engine sets the image. To set the image of the scrolling background, you could create a new GreenfootImage the size of the 'png', fill it with white and draw the 'png' onto it before setting it as the scrolling background image.

@EduandErnst, when I said 'Try drawing ... " in the last comment, I meant as an experiment to see how it works -- not to change the way the scrolling engine sets the image. To set the image of the scrolling background, you could create a new GreenfootImage the size of the 'png', fill it with white and draw the 'png' onto it before setting it as the scrolling background image.

@EduandErnst, when I said 'Try drawing ... " in the last comment, I meant as an experiment to see how it works -- not to change the way the scrolling engine sets the image. To set the image of the scrolling background, you could create a new GreenfootImage the size of the 'png', fill it with white and draw the 'png' onto it before setting it as the scrolling background image.

@EduandErnst, after further thought, I have come to believe that what you are experiencing has to do with .png files supporting transparency and .jpg not. Try drawing the .png file onto the background image, after filling the background image with color white if needed, instead of just setting the image as the background image. As the backdrop of your world window, the background image should be completely opaque (you should not be able to see "through" or "beyond" it).

@EduandErnst, I am not quite sure what you mean. Maybe you can start a discussion thread and link an image of what you trying to describe.

Forgot to include which keys to use to change the size of the worlds. They are the plus and minus keys to the left of the backspace key on standard keyboards. (now noted within the scenario description).

@Super_Hippo, I should allow block to spawn on the right edge. However, if I do restrict spawning blocks on the left edge and continue to spawn the player at that edge, then if the second column is tall and the first column is short, the player will be stuck indefinitely (well, until a column does complete fill to the top, which would be game over, anyway). So, that would add more responsibility to the player: to push blocks to the left edge to keep it close in height to the adjacent column.

@Super_Hippo, thanks. Atm, yes -- you die if a column fills to the top (kind of forces you to maintain a level playfield). However, since you really cannot do anything about the left and right columns, maybe I will restrict spawning at those location but still allow blocks to be pushed along those edges.

@Super_Hippo, it would be easy enough to just pass the game world to the instruction world and return to it when the back button is clicked.