The piece colors don't look very aquatic to me; polution of the oceans isn't that bad yet... I would more expect something like #C0E0FF and #40D09C.
With pieces that capture as locusts it will be very difficult to checkmate a bare King, and consequently, the game will be very drawish. If my King can reach a corner (and I don't see how you could prevent me from doing that already in the opening) it has become impossible for you to win. None of the pieces can attack the corner, so my King is absolutely safe there. I can abandon all my other pieces, and it would still be draw. You can attack all squares around it, but that would stalemate me if I am in the corner, and just make me step back into the corner otherwise. (Compare the KBPK end-game with Rook Pawn and wrong Bishop.)
Variants with pieces that capture like this usually have an extra rim around the board where you are able to land after such a capture, but cannot otherwise move to (e.g. Roccoco). Of course you could declare stalemate a win. That would solve the safe-corner problem, so that you might be able to force stalemate with two Tritons. Note that Prawns, Seahorses and Nereids can never attack any edge square.
You could also make pieces check the same way as they move without capture, rather than as they capture. But that would make all checkmating of a bare King just normal Chess, which probably is less fun.
The piece colors don't look very aquatic to me; polution of the oceans isn't that bad yet... I would more expect something like #C0E0FF and #40D09C.
With pieces that capture as locusts it will be very difficult to checkmate a bare King, and consequently, the game will be very drawish. If my King can reach a corner (and I don't see how you could prevent me from doing that already in the opening) it has become impossible for you to win. None of the pieces can attack the corner, so my King is absolutely safe there. I can abandon all my other pieces, and it would still be draw. You can attack all squares around it, but that would stalemate me if I am in the corner, and just make me step back into the corner otherwise. (Compare the KBPK end-game with Rook Pawn and wrong Bishop.)
Variants with pieces that capture like this usually have an extra rim around the board where you are able to land after such a capture, but cannot otherwise move to (e.g. Roccoco). Of course you could declare stalemate a win. That would solve the safe-corner problem, so that you might be able to force stalemate with two Tritons. Note that Prawns, Seahorses and Nereids can never attack any edge square.
You could also make pieces check the same way as they move without capture, rather than as they capture. But that would make all checkmating of a bare King just normal Chess, which probably is less fun.