Pipe Dream (a.k.a. Pipe Mania, or about a thousand different clones), I’m constantly surprised that more people haven’t heard of it.
Pipe Dream is a puzzle game that does away with the standard ’sort things and make them disappear’, and instead has you creating a network of pipes from random pieces to contain the flow of a mystery liquid. What the liquid is changes in each incarnation, but it really doesn’t matter what it is.
The liquid will start flowing shortly after the stage starts, with the length of this initial delay diminishing as the levels progress. Depending on the version and the level, you will have one or two goals to achieve: make the liquid flow through a certain number of pipes, and make the liquid flow through a certain number of pipes while making it to the end pipe.
It sounds easy enough, but you can quickly start to panic as you realize that the liquid is slowly but surely progressing and you aren’t getting the piece you need to connect the two halves of your pipe network.
Not that that’s ever happened to me.