You do need to "make a switch" for every chest. To animate, on the first page after you choose to open, as you said, left, right, up, then have it give you whatever or attack you, then turn on the switch. On the second page have the image as the chest open, or if you want it to dissapear nothing. Unless you have a message display of what happens, you might want to add a wait command after the animation, to make sure it shows the animation before turning on the switch.