I am absolutely addicted to these games. It is a really good workout for your brain! My 9 and 6 year old love to sit with me and help me solve the mysteries. I would say that these are definitely family time games. Even on the junior detective mode, an adult should be around to help make suggestions.
(I have Windows XP, and they work just fine for me.)
These games are great! my daughter, who is 14, and I love to play them together. I also have Windows XP operating system. I had to update my Flash player to play it, but that is free online. If you use the analyze my computer at the installation of the game it will tell you what you need to do to make the games play correctly.