I'm disappointed in this as well. I liked having my fish on the screen. Guess it won't matter when the YTTV and Roku spat continues and I move to Chromecast with Google TV.
It doesn’t only do that on the aquarium it does it on almost everything.
Then why would anyone actually buy a screen saver that will never work except on the home screen? Something really fishy here.
It also works if you let an app go idle while video isn't playing.