one of the best free rogue-likes ever made. only flaw is that it sometimes lagged playing on a browser in newer versions of Firefox(back when FF still supported Flash).
haven't tried this in NG Player yet.
EDIT: runs smoothly so far....
BUT starts leaking memory after a few hours of gameplay? it starts hogging over 1 GB of RAM for some reason and the number keeps going up. this game is not big enough to use anywhere near 1 GB of RAM. also the fog effect and the music seems to lag the game sometimes on my potato machine.