I have played Exiled Kingdoms, an AMAZING old-school RPG, on and off for a couple years on Android. It’s updated often, contains tons of player choice events, and has four classes with multiple build variations, so replayability is massive.
They just released a PC version on Steam! Go check it out while it’s on sale here: http://store.steampowered.com/app/788270/Exiled_Kingdoms/
Honestly, I prefer the mobile version, but we’re PC gamers in this forum.
Its graphics are pretty poor, and it was originally made for mobile and ported to PC, so there are some control issues that are still getting polished, but otherwise it’s a gem.
It’s very difficult but not overly so. It plays almost like Diablo 1 with rest to recover a la D&D.