Rikudo**/***** essentially are made up of a (partially hidden) string of the numbers 1 to N embedded in a figure consisting of hexagons.
I must admit I never figured out how to efficiently draw a couple of hexagons, so I’ll use squares arranged alternating in adjacent rows – the net result is identical in terms of the number of adjacent borders.
Usually, the number 1 and the highest number are given. Sometimes the author puts a dot on a border to indicate that the adjacent numbers differ by 1.
Solving strategies
A straight line between two given numbers, with the length of the line equal to the difference between the two numbers
Two adjacent hexagons have numbers which differ by two
No dead ends
Though there are several routes from 6 to 10, only 1 will fill the red square.
You can check your solution here
justpuzzles 