I came up with this idea when I was creating a program which generated standard sudoku puzzles. Usually when I play games which contain a right angle grid, I start thinking of converting the game into a hexagonal grid. Later I found out that this same grid had already been used for one variant of sudoku. But my rules are a bit different.

Here's a rather easy puzzle for a starter:

The rules are as follows. Use the numbers 1 to 9 to fill the whole grid. No number must occur twice or more in same round unit of 7 cells, same row of 7 cells or same row of 5 cells. Note that the rows run in three directions.

Things that differ from standard sudoku

The units consist of 7 or 5 cells, not 9. But this variation uses 9 numbers nevertheless. This is for a reason. With only 7 numbers, the only solution would always be that each round unit have an identical pattern of the 7 numbers. By adding numbers 8 and 9 this puzzle got very interesting!

The fact that not all numbers fit in one unit makes solving very different from standard sudoku. Some strategies you can use, some strategies are just not available here. I haven't even figured out very much special strategies.

Here are some more puzzles. Tell me what you think.