NetHack VS POWDER

Prior to 3.1.x the dat subdirectory didn't exist yet but data.base was present somewhere, possibly in the src subdirectory instead. I don't know whether it goes as far back as hack 1.x or even nethack 2.x. The source code for a bunch of old versions is present at https://nethackwiki.com/ but I'm not sure whether the data files are all there too. The source code for the most recent released version (3.6.7) is... Source: 11 months ago

I am not sure what extra benefits the Steam version has, but the game is available for free either as download on nethack.org, or to play online at something like alt.org/nethack or hardfought.org. Source: 11 months ago

You don't even need two people to play D&D, Nethack is great! Source: 12 months ago

I've always been fond of the last quote on nethack.org. Source: about 1 year ago

It was discussed here last fall, when the home page for nethack.org was updated to mention it. The blurb includes a few other tiny screen shots and says the exhibit is scheduled to be open until mid-July. Source: about 1 year ago

Powder is a fun roguelike for the gba (and other systems). Source: about 1 year ago

Going into slightly more obscure stuff, POWDER fits your criteria - original game, 16x16 default tile set with other tile sets available, Linux port available since the mid-aughts, etc. No idea if any distros had it in their repositories at the time, I only really played it on the DS. Source: almost 2 years ago

I had nothing to do with roguelikes for many years, but one day I discovered POWDER, and it all suddenly clicked! Now roguelikes are muy favorite video game genre. No thanks to NetHack :). Source: almost 3 years ago