Way back when I first began to shrink away from the outdoors and all of its fresh air and sunlight to become glued to the internet (let's say 2004 or 2005), there was this browser-based riddle game that was pretty popular at the time.
To my 14-15 year old brain, it was pretty much impossible to get more than three levels in, and I gave it up, but I remembered it to this day as that cool browser game that was way over my head. But I never remembered the name, and my google searches of "old browser puzzle game" or whatever I had searched for in the past few years never turned up the same site.
Today, "The hardest riddle available on the internet" was on the front page of reddit, and I idly clicked it, and lo and behold, there was notpron.
Good news is that it's still really cool. Bad news is that gone are the days when I could blame my youth on only getting to level 5. I'm still stuck on level 5 right now.
Apparently, the creator of notpron believes that it's probably impossible for a single person to get through the whole game without cheating, as it requires a lot of skills and sometimes even getting up from your computer and interacting with real objects to solve a level. Sometimes it requires downloading the picture and tinkering with it. Sometimes it requires going into the source code of the page and figuring something out there.
Some people with saint-like patience and the integrity to not cheat have reported spending months turning one level over and over in their heads, trying to figure out how to progress.
Point is, shut up and look at this: http://notpron.org/notpron/levelone.htm
If you get further than Level 5
, no spoilers, and also I hate you. I'll figure it out. Give me ten more years.
Edit: I swear I meant I was stuck at level 5. What does it even want from me.