Aquapalz Jellyfish - unhappy?

My Aquapalz Jellyfish is unhappy and I've no idea why. I changed her water, the temperature is right, she has 5/6 happiness hearts.
But she still keeps turning away and making the unhappy sound. She also refuses to play with her toys or games with me.
Anyone knows what the problem might be...?

Did you check the oxygen level...? I think there is something to do with the top flap too. I never figured it out though.

Everything was ok. The water has been changed earlier and was in perfect condition.
And she was not sick or anything.
I think she was simply angry that I ignored her for about an hour. xd

I used to have the Dolphin but sold it. These pets were hard for me to understand via their moods, and would die so easily as babies. But I think it has to do with tank decorations maybe?

You know, that actually might be!
I am loving the jellyfish so far and intend to keep it. ^^
Well, the packaging says something like 'your own pet with attitude' so I'm guessing that's her attitude.

Maybe, dunno. I really tried to like my Dolphin, and they're kinda hard to find, ish? But yeah, it just got boring too quickly. Had neat features, but wish there was a lot more to it.

It's not really boring for me. ^^
It's needy enough to keep me interested and has beautiful animations. The water feature is really nice and the games are fun too. Idk if they are hard to find, but I am really glad I got it cause it's one of best odd pets I have in my collection.
She was angry with me this evening too and I am pretty sure it's because I didn't play games with her. I think she just needs interaction with me to be fully happy. I love this idea cause it's really making me feel like I am taking care of a pet.