Unrelated to the creepy dude in that thing, but made me happy to think about because it's one game that I've thought of that actually sounds possible to create!:
It'd be interesting to play a rogue-like where the only things you retain between lives (a la Rogue Legacy) are sort of... Adjectives, or other modifiers, that you can apply to the random-world generator.
I.E. you pick up "stone", and apply that to your next world, and now you're playing in a world that has a stone motif. Maybe it'd be caverns, maybe it'd be a ruined stone temple, maybe it'd be a rocky badlands, anything that can be concievably listed under "stone" would be up for grabs. Perhaps you would be fighting stone-like enemies, golems and such?
And if you apply multiple modifiers, then it's constrained further. Perhaps you add "Heat" to "stone", so now you might be playing in an Egyptian temple, or perhaps in Petra or Mojave-style stone/cliff-face city? Or maybe you're in a lava world. The badlands might pop up again here, but have a higher chance than previous, because now you have 2 modifiers for it, "heat" and "stone". And the enemies would be a mix of "Stone" enemies and "heat" enemies, as well as the items and abilities you pick up during that run (which leave you like a normal old-school roguelike upon death.)
Presumably there could be a set number of modifiers you can use at maximum, like 3 or 4, say "Ancient", "Stone", and "Cold" and perhaps "Death", so you could be playing in a frozen wasteland full of bones and fossils, or in an old Norse burial ground.
I think that'd be very fun to play. Each run through gives you 0-2 new modifiers to apply to your next play-through, depending on how far you get.