I played: Candy Box
Candy Box is getting a lot of attention. I'm enjoying it. You should probably go start playing it before you read on, because it's kind of like Frog Fractions or Drop a Beat, Giuseppe! or Dragon Drop (and if you're not sure what I'm talking about, go play all those too).1
I'm spending way more time with Candy Box that I expected. Even after it opened up what I saw at first was an ordinary energy-waiting-spending mechanism. These are common in F2P games but lately they're found even in other styles2 of game, and I hate them.
But for Candy Box this is another layer of trickery. If you're really paying attention you get on an exponential feedback loop within about an hour of play. There's the "opening up" after a few minutes, but then also a second at that point, where you start to get meaningful choices on intervals comparable to the time it takes to make the choice. The candy energy becomes almost irrelevant (say, as relevant as how many potions you have in a Final Fantasy game) as you start to consider how you can use the potions and scrolls available. Eventually you get the cauldron and navigable levels and it's more like animation lockdowns than waiting for energy; the scales are so short and there's so many near-term options at each juncture.
What really drew me in was the mechanism of the Wishing Well (although a similar choice appears with smaller magnitude at other points in the game). It gives you a one-time ability to gain items proportional to the items you have. In a game where the decision space unlocks gradually a one-time ability comes with worries that you might not even know what's important. Between the exponential power curve and granting this ability it becomes a game about patience rather than just a game in which I must be patient.
When you have to wait two days and can pay $10 to remove that, it's abusive or at least stressful in a bad way. But what is it when you can wait an hour or two days or five days and then invoke an ability - exactly once - to multiply your energy by eight? Then it becomes a game of patience and suspicion. How long can I wait before invoking this? I know if I do it after an hour I'll get to do this new thing. I don't know, but suspect, if I wait a day it's going to open up much more. I don't suspect, but might believe, that if I wait a another day it's going to open even more.
So it's kind of a game of chicken, but against a static system: When do I think the designer stopped implementing new things? Inevitably the comparison, when would I stop adding new things? How much do I think I don't know? It's constantly asking me that, and I think that's an uncommon question in videogames.