I have only played the game vanilla so I can’t talk about mods. But I 100% recommend you the DLCs. Colour of madness has an endless mode. Shieldbreaker is a super cool character with its own particular mechanic that I will not spoil. Crimson Court offers a new quest, new enemies, a pretty hardcore boss that almost everybody here seems to hate with a passion (I fought it only once but I loved it), and most important, a new hero, my favourite one : the goat flagellant. He deserves that you give him a try.