Salt & Sanctuary is basically Dark Souls in 2D, with proper RPG mechanics (levelups, skill tree, etc), and it plays well enough with mouse and keyboard. Mouse for aiming and attacking, keyboard for movement. Much, MUCH smoother than Dark Souls' M&KB controls.
Vigil is also strong on the RPG elements, with a traditional XP system and a unique skill tree for each weapon, but it gets a bit easy towards the end. Keyboard only, no mouse, but also controls really well.
I haven't played Bloodstained: Ritual of the Night yet but I heard that this one is also strong on the RPG elements.