BirdDuko

Tap a square once to cross it out. Tap a crossed square again to place a bird. Tap a bird to remove it. Drag across squares to cross out several at once.Rules: one bird per colour patch, one per row and column, and birds may not touch, even diagonally.A wrong bird costs a heart; lose all 3 and the level restarts. Use Hint to reveal a bird and Undo to step back.