I noticed that a few other people here (aside from me) play the free game, Clicker Heroes.
You start off with only a mouse click and end up ruthlessly addicted to this world of automated damage-per-second fuckery to kill monsters and bosses.
I've spent a wee while on it in this playthrough, I'm currently at stage 86.
You can play the game on the website or through Steam.
Steam store page: http://store.steampowered.com/app/363970/
Drop some screenshots and stuff below.