I wish so much that it would have been the case. I repeatedly made mistake on mistake by confusing the pieces and the given clues before trying an approach very similar to yours, but at this point I was just so much frustrated and stressed by the perspective of messing up the second round after having been pretty slow on the first one that I was never able to enter in the puzzle during the last minutes. The puzzle itself was not a too bad idea, there was definitely some originality in this, but the exploitation of this idea could have been way better.
Anyway your own solving time was quite impressive - and added much to my stress, by the way. Thanks for that !

(Just kidding of course, but true nevertheless)

I used a similar approach, I placed pieces so that they covered the bottom half of the cell where the piece should be placed and the top half of the cell below (e.g. if the piece went to R3C4 then I covered the bottom half of cell R3C4 and the top half of R4C4 in the grid). It worked fine until 20- pieces, but it became quite confusing when I placed more pieces in the grid (and I forgot 2 or 3 times that pieces belonged to the upper cell in the grid...).

One of my teammates mentioned after this round that it could have been a good strategy to place 30-35 pieces in the grid then turn all of them so that the numbers become visible and solve it as a regular Sudoku puzzle. That sounds a good idea but quite risky because it might happen that having 30-35 numbers in the grid isn't enough to solve the regular Sudoku quickly and in this case you still have to raise the pieces... I didn't check this technique yet but I'll give it a try later.

Edited by wicktroll 2011-11-14 12:48 PM