My previous 6x6 global entropy puzzle:
Double Entropy
RULES:
Normal 6x6 sudoku rules apply: Place the digits 1-6 once each in every row, column and 2x3 box.
Global entropy: Each 2x2 area in the grid must contain at least one digit from each of the three entropic sets: {1,2}, {3,4}, {5,6}.
Arrow: Digits along an arrow sum to the number in the attached circle.
Kropki Dots: Digits in cells joined by a white dot are consecutive.
Click on the puzzle image to play