Eat or erase all the fish on the field.
"Sakana" is Japanese for fish.
Operate the walrus.
Walrus can move up, down, left, and right, but cannot stop until hit another panel.
So walrus can only move in the direction of the panel.
Walrus will stop when it hits the panel.
The panel that hits is pushed out in the same direction as it is.
If it hits another panel, the original panel will stop there and the panel that hits will be pushed out.
Walruses eat the fish on the way.
Panel erase the fish on the way.
The game is finish, when eat or erase all the fish.
The game is over, if fail to move and cannot move in any direction.
The level goes up depending on the speed of clearing.
As the level goes up, the number of fish increases and the stage becomes complicated.
Can "Undo" and "Retry" as many times as like.
Clear all 10 stages, the total score will be registered on the leaderboard of the game center(The score is higher when eat fish than erase.).