Aquarium is an acrylic packing puzzle which goal is to fit all 3 octopuses into the "aquarium" (frame)
It was created by Russian designer Vladimir Krasnoukhov.
The puzzle fits perfectly the theme and the colors are well chosen. Still, note that the colors may vary and personally I prefer mine than the ones shown on Puzzle Master website (yours may be even nicer!).
I liked a lot the quality of the material used (like all the previous Vladimir's puzzles), the colors used. Especially the transparent color for the octopuses (yellow would have been weird) and it's very funny to try putting the tentacles all together.
As for the difficulty, it's not easy, but I would rank it as "moderate": you will be challenged without frustration and you can even let you friends.
I liked a bit less that there are no surprises, nor tricks involved. You 're expecting to do what you initially thought you would have to. So the solution could have popped in your mind before playing for hours. You can analyze, like what I did, the shapes and with just that you may come to a solution (there is only one by the way).
To conclude: a very nice looking puzzle, nice to share with friends. A bit on the easy side, but still far from being easy.