Platform games are one of the first forms most new game developers attempt, and one of the fundamental movements of a platform game is the jump. When you add the jump motion, your character is immediately able to jump up onto new levels and progress further through the game. Adding a jumping motion into Game Maker 8 is easy, and you can have your character jumping in only a few minutes.
Add the step event to the object you want to make jump.
Add the Check Empty action located in the Control tab to the step event. Set Y to 1 and check the relative box.
Add the Set Gravity action from the move tab to the step function. Set the direction to 270 and the gravity to .5. This will apply gravity whenever the object is not on top of a solid surface.
Add the Key Press Up event to your object.
Add the Check empty action from the Control tab into your new event. Set Y to 1 and check the relative box.
Add the Set the Vertical Speed action from the Control Tab to your event and set the speed as -10. This will make your character jump into the air as soon as the up key is pressed. The gravity will quickly bring the object back down to the ground completing the jump.
Adjust the vertical speed to increase or decrease the distance your object can jump.