When I mentioned to my friends that I'd finished playing Thaumistry, the first thing they asked was: "Is it old-school?" What a delightfully multivariate question! The answer is "yes and no", of course, but let's not drop it there.
Bob Bates is old-school, because he wrote for Infocom. But he's at the tail-end of Infocom's history: Sherlock and Arthur were two of the final titles in the Infocom canon, as the company tried to push forward into audio and graphics. So in that sense, he's modern. And Bates is better known for his work on the graphical adventures of Legend Entertainment. That was "modern IF" in the 1990s, but it's pretty old-school today, isn't it?
Thaumistry was published with Kickstarter support, and there's not much more modern than a Kickstarter game. Someone will say "how about a game that avoided Kickstarter because that bubble has burst," but let's not be cynical. I like to point out that Hadean Lands got 700 backers and $31000 in 2010, whereas Thaumistry got 1000 backers and $35000 in 2017. That makes the Kickstarter audience for parser IF look awfully stable, doesn't it? But my very rough comparison of the backer lists doesn't convince me that they're the same crowd. The lists overlap some, but they're not primarily the same group.
I don't know what the moral of that is. I backed the Thaumistry KS, in case you're wondering.
What I'll say is that even though Bates is a generation older than me, Thaumistry was constructed within the context of modern IF. I recognized many of the names who tested the game and helped develop the app. I was around when Bates asked coding questions on the intfiction forum. He used TADS 3; he took advantage of a modern parser. The game lays down prose as needed, free of that 1980s sense that every word is a precious commodity. (Or the late-1970s sense that every letter is! Ah, Scott Adams.) It understands that X is short for EXAMINE. It lets you UNDO three whole times in a row.
The game adheres to that principle (more modern than Infocom, but older than Myst!) that the player should not have to worry about getting stuck in a corner and needing to start over. There is one spot where you can die but it's heavily signposted. ("Now might be a good time to save your game," the game says. Even if you don't, UNDO has you covered.) It also supports autosave, which is absolutely necessary for any modern game -- not just IF!
And yet, with all this, Thaumistry feels... old-school. Not the implementation (solid) or the puzzles (reasonable) or the writing (energetic, usually funny). It's about the way the protagonist is presented. Or not presented.