Anchorhead’s great. Photopoa’s a good introduction to the medium, but Lock and Key is probably my favorite by that author. You’re charged with designing a dungeon to foil an endlessly resourceful adventurer, and you have to use logic and trial and error to figure out how to make him expend all of his resources before delivering the killing blow.
Once you get used to them, the parsers for TADS/zcode/Hugo games are pretty solid; assuming the author took the time implement a lot of synonyms anyway. The difficulty really is in the classic adventure game puzzle setup, wherein you have to find mot just a solution, but the specific solution the author implemented.
I used to play a lot of IF and three computers ago had a big block of Hugo code on my hard-drive that was supposed to be a game.
I’m always suprised no one’s created more mobile support for traditional IF. It’s not the kind of thing I really feel like hauling out a laptop for any longer, but if I could play it on my phone during off moments, I’d probably get back into the hobby a little bit. I know there’s Frotz, which plays zcode games in ios, but it doesn’t support the newer games, and I’ve played most of the classics long ago. I was actually looking for a mobile TADS interpreter when I first discovered CoG.