It's staggering how much effort video game developers will put into hiding secrets, gags, and perhaps even entire quests, characters, or storylines in their games.
In fact, the only thing more impressive is the lengths players will go to uncover every last secret residing within a game, be it tinkering around with the source code, brute-forcing their way to success, or even - gasp - venturing out into the real world.
Virtually every major game released these days, whether AAA or indie, contains a sneaky Easter egg or two, but these 10 games ended up putting players through the wringer in the service of uncovering these bizarre secrets - and figuring out why they were in the game to begin with.
Whatever the reason for the Easter egg's inclusion - a dev team with a little too much time on their hands, typically - they tested players' observational abilities to their absolute limit, and most often required fans to band together online to figure everything out.
Whether the actual Easter egg itself was worth all the effort made to unlock it, you can't argue with each developer's aggressive commitment to driving their fans mad...