PARANOIA

So, you may have played this before, possibly in the newspaper even. There's two pictures side by side. At first glance, it's just two copies of the same picture. But no, there's something different between them. Maybe a few very subtle differences, even. And you have to spot all of the differences and then report what they were to solve the puzzle.

That is what Paranoia is, but it's done as a text adventure. You are in a room. There are various objects in the room. You have to decide what if anything about the room is different between the last time you pushed a button. You must use every sense here to detect any slightest change.

Paranoia responds to almost every single thing you try to interact with correctly. Not quite everything but most everything is either correctly implemented as scenery. I suppose it achieved this by keeping it all in a single "room" (from the player's perspective, anyway, I guess that this might be implemented as a bunch of very, very similar "rooms" in the game engine with small differences).

That's it in a nutshell. If you love difficult puzzles, you will probably love this. Accept the challenge! If not, this probably isn't your thing. Paranoia is well implemented.