Not too long ago, I've tried out a tough (but very fun) game. It's called Mibibli's Quest.
The game is quite addicting, as it's a great throwback to the 8-bit NES days (but some parts just drop the 8-bit soundtrack and play full instrumental stuff). But I must warn you--it's HARD. Even on the easiest difficulty setting, it can knock you for a loop at some parts if you're careless.
And what's cooler? It'll soon come out on Steam. And unlike the GameJolt version (which I played) or other versions, the Steam version will have an actual final boss.
Until then, if any of you are curious to know what Mibibli's Quest is, permit me to show you.
This is a great game for fans of the absurd. And want extra challenge.