Easy boards are graded by technique, not by feel: every one of them can be finished using only the starter toolkit — unique numbers are safe, a triple's ends get shaded, a sandwich's middle stays white, and each shade you make circles its neighbors and eliminates their duplicates. If you can run that cascade, the board falls.
This is the right tier for learning to trust deductions instead of instincts. New to the game? Read the how-to-play guide first, then work through a few of these.