Did you explore the whole tank? You have to scroll to the right. It holds a million gallons (or so). Did you try clicking on a fish or plant?
Check out TANK 2 - same fish, but more of them. Watch for more tanks and new fish expected to arrive soon.
Here is how i created the tanks:
1) I started by creating a water background in Photoshop, to set the mood.
2) Next, i created animations by drawing and scanning the individual animation cells.
Here for example, are the basic Porkfish cells in development:
3) Once the drawings were scanned as line art, i added color in Photoshop:
4) I then put the cells together in GifBuilder to create animation loops.