After completing 8061 Gateway of the Squid, I would say the overall impression is not really that good, the minifigs, which includes the Squid warrior and divers, are quite impressive, especially the very cool Squid warrior, but the squids and the temple are disappointing.
The design of tentacles in one single long piece is not ideal but still acceptable, but the squid body and claw do not appear realistic to me, same for the smaller octopus, I understand it may not be easy to design these two sea creatures, but in such forms I just feel that they look odd, the octopus looks more like a white spider to me.
The color mix of the temple is a strange contrast of gray and tan, which does not look harmonious. The mechanism to open the gates through rubber band is hard to use, wouldn't using technic parts provide a smoother movement?
I think Lego is very smart in providing the colored keys, many would be tempted to buy more Atlantis set to collect all 5 colors, but I feel that there are poor designs in some elements, which would weaken the value of the Atlantis theme despite having some very cool minifigs.