Another "True Roguelike", Dungeon Crawl Stone Soup (DCSS) started out as "Dungeon Crawl" in 1995 and has continually evolved since. There are tons of playable races and classes, and it can even recommend the ones that are easier to play ๐ It's very easy to jump into, you can play in a browser with tiles and mouse support in less than a minute. DCSS is still actively developed, there are tournaments and you can observe in-progress online games.
Recommended to use keyboard with a bit of mouse for examining and targeting. The graphical tiles are easy to understand, the defaults are convenient like auto-pickup of more valuable items and automatic melee attacks. Still, expect to press ? ? a lot to review the controls. There's also a quickstart guide from ? ^. I've tried the Android version a year ago and did not like the interface. If offline is your thing, you can download the version you like and keep the save files on your computer.
You start off alone on Dungeon Level 1, as is tradition. It starts off not too difficult; the monsters are weak and you are strong. Later you will have to proceed carefully, there can be large hordes with more elite enemies mixed in. A bit like a turn-based Diablo. Expect to die, but "winning" might be easier than Nethack for example. There are all sorts of metrics you can use for a "better win", typically a number of runes collected before ascending.
The most interesting aspect for me was the religious worship system. Different gods have their own rules and rewards that will incentivize how you play the game. For example, Xom the god of chaos will do all sorts of good and bad things, but if you bore them... they will do more bad things, more often.
Summary: Fun traditional rogue-like, lots of features and more approachable than Nethack.
