We found this Tetris-reminiscent puzzle game by Alain Brobecker. The goal is to tile a 7-by-7 square using wooden pieces, starting from a given configuration. Here's an example:
We solved most of the puzzles, except for puzzle number 30, shown below, which proved somewhat stubborn:
To save my dignity (at least to some extent), I wrote a mixed-integer linear program to find possible tilings.
This is a simple instance of a covering problem. (See also Golomb 1994, 81--83.)