Lots has been written already about Mythos, a free-to-play Diablo-esque MMO from Flagship Studios (makers of Hellgate London), and there are plenty of guides (including our own) to look through if you want some insight on what the game is like. And here's another-- our friend Stropp has punched up another preview of levels 1-5 in Mythos.
Like a lot of other people who've played the game, Stropp compares it directly to Diablo 2-- lots of running around, clicking, and just generally crushing everything in your path. As we've heard before, there are three classes and three races in the game, so while the game itself is a little simpler than the major MMOs (it is F2P, after all), the gameplay is solid and well-traveled enough that it stays fun. There's also an achievement system, apparently, in which you can win titles that actually grant attributes for your character. Sounds cool, even if it's not quite as developed as some other games yet.
Mythos is currently in very, very open closed beta-- they'll give away a beta invite to almost anyone if you ask nicely enough. The buzz just keeps going-- it may be the free-to-play game of 2008.