Blue Balls Of Evil
Remember that we use the term collision to refer to any moment in the game where 2 objects occupy the same place on the game field. We have already dealt with one collision in the game, when the blue ball touches the green edge of the maze.
To get our game to the stage where it becomes playable, we need to make sure that we handle the collision of the character object with any of the blue balls and when the character is moved over one of the grey squares that represents the end of a level.
Blue Ball Collision
Open up the character object's window. Create a collision event with obj_enemy_up_down. There are 2 actions to put in this event. First you need to play the uhh sound - you have already done something like this before.
The second action is to restart the room. This takes you back to the beginning of the level. To do this, drag in a Restart Room action.
You can duplicate this event for the other 2 enemy objects by clicking with the right mouse button on the event you have just made and choosing Duplicate Event.
End Of Level
The player moves up a level when the character is moved over a grey square. The actions for this are shown in the screenshot below. Study them carefully before doing this in your game. If there is another room, the game will load it, if not it will replay the level.
Save and test all aspects of the game at this stage.