Side scroll demo

I look at the code and i somewhat understand it. Yet i change something like the dimension (I change it all the way through) it compiles, i look at the scenario and get a gray Run, Act, Pause set and the game is like a 1mm square box. Do you know whats wrong? And the only way to get it back to normal is to delete the class and re-copy original.

Nevermind. I was didnt change the image extension from .gif to .jpg. Spent 1 and a half weeks on it then the dude next to me was like you need to change the extension....

@lirki At one of my scenarios I got the same mistake with this squarebox. For some reason everything works in Greenfoot. But as soon as I export it to .jar there is this stupid square instead of my game. Maybe it's a bug in Greenfoot

@GameCode, best thing to do is create a new discussion (Discuss tab at the top of the gallery page) and talk about the problem, and give a link to your scenario. Probably it is actually something that you are doing wrong...

Hi. I found this scenario very useful, but I can't figure out, what should I change in code to make background scroll vertically. Can anyone help, please?

I want this code: https://i.ibb.co/WKNrNsq/1.png Where do I find him?