GameMaker tutorial / lesson with completed project files at http://www.gameprogrammingcourse.com in the RESOURCES section.
Understand how to code simple platformer game movement including climbing up ladders and climbing down ladders.
Check out hundreds of other GameMaker tutorials and lessons at GameProgrammingCourse.com
All these gamemaker tutorials will work with Gamemaker Studio GMS or Gamemaker Studio 2 GMS.