This is an advanced project that demonstrates how to make a scrolling background.
input/output, delays, simple loops, visibility, simple messaging, basic math, functions, simple events, simple conditionals, variables, simple variables, advanced costume handling, direction and turning, advanced motion, simple costume handling, simple sound playing, detect conditions, simple motion, resize actor, cloning, text handling, music and instruments, screen bounds, advanced events, program control, conditional loops, advanced messaging, layers, miscellaneous, advanced loops, advanced math, simple drawing, graphic effects,