One of adventure gems is added to Steam catalogue.
Nostradamus: The Last Prophecy.
http://store.steampowered.com/app/287720/
It's sold for 20€ elsewhere (gamersgate, adventure shop, amazon) and on steam it's now with promo price only 7€!
Buy now! Even if you're not into adventures. This is one of those games you probably never heard of and once you start cracking it's puzzles you won't believe how come noone ever mentions it as a brilliant game.
Oh and a correction. Steam lies. The game developer is now defunct Kheops Studio not some Anumen and Microids whatnot!