Remember the old concentration game from many years ago. You can make your own version. you will need thirty clear plastic envelopes. They can be make from cheap clear plastic lunch bags and clear plastic tape. Poster board can be used for making the large frames. You will also need to make some blue cards with the embossed numbers for each of the bags. Of course you will need a frame to hold the puzzle background.
Lastly you will need a puzzle to use as the background. You can use your favorite drawing program the will let you import pictures. Gimp is what we like to use There are thousands on-line that you can use or even use your own. Such as:
The sky is the limit with your imagination. More information at: http://en.wikipedia.org/wiki/Concentration_%28game_show%29