(You can have a look at the introductory example of gamemaker official development.
Official Gamemaker Tutorial 1945_ 7.gmk
Official Gamemaker Tutorial Catch_ the_ Clown.gmk
Gamemaker Official Tutorial DG Treasure.gmk
Gamemaker Official Getting Started Tutorial fps6.gmk
Gamemaker Official Tutorial isometric.gmk
Gamemaker Official Tutorial MarioAItutorial.gmk
Official Gamemaker Tutorial make_ 4.gmk
Official gamemaker Tutorial parallax.gmk
Official Gamemaker Tutorial parallel.gmk
Official Gamemaker Tutorial platform_ 5.gmk
Gamemaker Official Tutorial scaling.gmk
Gamemaker Official Tutorial treetracing.gmk
Gamemaker Official Tutorial tutorial1.gmk
.....)