In my hurry I dint check the rules :P

But my guess is that its and irregular sudoku with all regions not being marked.

Sample puzzle with solution, but not sure what the rule is

Same colours are start and end of a path and must be connected. The path will become an extra region. Lines are just walls blocking the path as in a maze. There are no Irregular regions, there is no concept of regions beyond a path. Personally I like Riad's version better for crossover round, without regions, players will say it is not a Sudoku.