Four Winds. Divide the grid into several regions; each region must contain a number in its “capital”. All other squares in the same region must be either in the same row or in the same column as the center of the capital. Each region must be connected; that is, any cell in a region must be able to be visited from any other cell in the region by moving orthogonally along the squares in the region. Each number tells the number of squares in its region excluding the capital, so a number of 0 means that the region is composed of only the cell with the number itself.
This puzzle has the Unknown and Different variants! The numbers are replaced by question marks; it’s up to you to figure out the numbers. Additionally, all the numbers must be different.
Easy to medium if you have tried Four Winds before. Otherwise, probably medium with a little spice of hard.
UPDATE 26-Oct-2012 22:46 UTC+7: Fixed an ambiguity near lower-left. By changing the right part. Yay.
And the second puzzle!
Tetro Stack. Perhaps the hardest puzzle so far in this blog?
Why is the latter a special puzzle? It was really hard (all difficulty are in my opinion) that I think I haven’t managed to discover a logical way, and I think I haven’t tested all possibilities. I’m not even sure that it has a single solution, hence the singled puzzle. This also makes it easy to remove it if it apparently has more than one solution. Yay.