If you're a nanoblock fan and you want a good challenge then this ocean set may just be what you're looking for. These are NOT standard compatible bricks, these are much smaller in size.
There are a total of 3 sets sold separately:
6622 Ice - Polar bear, deer and penguins is 1880 Pieces.
6623 Land - Birds, crocodile and hippo is 1860 Pieces.
6624 Sea - Whale, dolphin and shark is 1950 Pieces.