This is a game of Pelmanism ("Pairs"), where you have to use your memory to match pairs in the shortest possible number of attempts. The program has been updated (and upgraded) from the previous version which appeared on the .net site. I now realise that that previous version contained portions of rather ghastly coding which I hope has now been improved. Younger family members may find this program of more interest.
You will need the User Manual (apologies that the title inside this document is incorrect).