Do not bother fighting the aliens or criminals since will just go away eventually. Also, do not approach them or else they will take you back to your room. To make them go away so you are not stuck in your room, save the game, and turn off the DS off. Turn the Ds back on and change the time to what ever time you are supposed to defeat the criminals or the aliens. Start the game and walk around a little bit before saving the game, turning it off, and turning it back on. Change the time to the actual time and you are good to go.