A really good design. Would totally work in the game. A potential winner. The details are great, the anchor, the boats, the pufferfisch in the arm...
You want a crit? Lets see theres not much to say anything about. The left arm looks a little short, its unclear to me if it is like this because it goes into the background or because it actually IS short.
The lightning in the lower right part (leading nicely to the human) is a tint too bright for my taste. Compared to the other lights in that picturea area, this one really flashs and is a rival to the contrast right above/ behind the monster. (Where we want to look)
Anything else? Peronally I would open the crab's hand at the right a little, to show more of what it is.
Hope that is usefull to you. Keep up the good work.