Dungelot is a free rogue like that I stumbled on and found enjoyable for a little quick entertainment. There is an online version, but you can also download the Windows and Mac versions using the links on the upper left corner of the Dungelot page. Or just use this for the direct link to download the PC version. There are also Apple and Android versions, but they cost $1 to $2.
You may want to check out the Gamezebo review of Dungelot. It also contains pictures of the game. They rate it 4.5 out of 5 stars.
There are plenty of videos available on youtube.
Finally, here is one more review that also contains a guide.
