If you are looking for a super-hardcore, very tough to beat roguelike, but with great lore and world-building, check out Dungeon Crawl Stone Soup (DCSS): https://crawl.develz.org/

You can play online but I play the 'tiles' version locally, the interface is better. To have any chances of beating the game, you must check out the wiki for guides and looking up monsters: http://crawl.chaosforge.org/Crawl_Wiki

Plus, it's open source.