Like Bejeweled and so many other simple computer games, the basic concept of Chuzzle is that you're trying to match like colors.
Popcap is actually the creator of both Bejeweled and Bookworm, but because of its partnerships - and of course, the popularity of its games - you'll find those games on Pogo, Shockwave, and Popcap's own site.
Known as a "swapping" puzzle game, Bejeweled's simple exterior hides an immensely addictive game just beneath.
The core mechanic is utterly simple, making Bejeweled -- in all its different incarnations -- accessible by all players, regardless of age or skill level.
One of the most popular free puzzle games is Bejeweled.