The YKTTW draft I'm currently sponsoring on TV Tropes ("All Stories Are Real Somewhere") is nearing its launch. I've got a few potential followups to work on next.
There are a few tropes I've noticed in puzzle games, particularly of the "falling block" variety. You know how in every game where you match different colors of blocks together, there's always a type of block that can be matched with any color? And there's always one that's dead weight and can't be matched with anything? I call them the Wildcard Block and the Dead Block, respectively. There's also that alternate mode where instead of pulling random blocks at a gradually-increasing speed, you have unlimited time and a very specific sequence of blocks to complete a predetermined puzzle. I call that one Puzzle Mode.
Then there's the one where win and loss conditions are removed, and you just get to putz around. It's in some puzzle games, but it shows up in all kinds of other games too, and it's something like a Free Play or Sandbox Mode.
And then you know how in stealth games, you can see a little cone in front of all the guards and security cameras that represents their field of vision? I'm not sure what to call that one, but I know it's a trope and I don't think it's on the wiki yet.