Koji I was able to test your application and I couldn't see any problem, according to me everything is working as intended. Every 30 seconds an enemy (the Active object named "Karma dispara Misiles") launches projectiles at the player (the Active object named "Gran Mazinger"). And he does this during 12 seconds. The type of projectile that is launched is not always the same, it depends on the Alterable Value A of the Active object named "Disparador de Misiles".
Here is a video showing that the attack is triggered every 30 seconds (Windows runtime):
https://www.dropbox.com/s/52183qqbuoct4cp/greatmaz.mov
My video is similar to the one that you have posted yourself. Can you confirm that they show the correct behavior?