Recently pulled down the Zork episode. Very nice, thorough, I didn't really think Zork would carry a whole episode but it did and then some!
Infocom games were indeed very hard, and I often just couldn't measure up, even with Invisiclues.
They did put out a couple of "easy mode" games, in fact if I recall correctly every Infocom game came with a difficulty rating right on the little corner label thing on the boxes.
One of these was honesty way too simple simple and called Seastalker:
It was ostensibly "Junior Level" and definitely the easiest Infocom adventure out there, but even though I was at the time, in fact, a kid, it was a bit too simple. You have a minimal set of locations and not much of a maze in the original seabase structure, but them once you left that it all took place in the cockpit of a submersible. It was very very short (like, 40 pts total or so), but I beat that.
More fondly remembered, for me, was Wishbringer:
This one was "introductory Level" and I managed my way through it. It was set on a mysterious island (or was it a peninsula?) with a mysterious post office and a glowing stone that granted wishes. It was a bit Alice in Wonderland, as I recall. One of the feelies with this one was a plastic stone which glowed in the dark, only purple instead of the stock-standard ghostly green that nearly all phosphorescent doo-dads at the time had. I became fascinated with it and after beating the game, put the wishbringer on a chain to hang near my bed as a kid.
I also played a fair amount of Infidel but didn't beat that one. Still, I have a lot of fond memories of the era and the company's games. They came from an era where having your game go unsolved was almost a badge of acomplishment for a designer: a fiendish win on the part of the puzzle-box-maker, against whom you were alone... with only a book with invisible ink (and a highlighter) and some graph paper to guide you.
I've yet to see Activision update the iOS port of Lost Treasure of Infocom so it will run on iOS 11, I hope they do get around to it. As much as you can play these or any other IF games on a solid Z Interpreter, there's something to seeing the original art, and representations of the feelies. It may just be nostalgia but its part of what made Infocom special and so considering how much we remember those feelies, they were a good idea! Using LTOI on my phone, I used to use voice recognition to try and input commands. It was clunky and awkward but it worked.
I've often wondered why IF hasn't made headway into the modern gaming space via the new voice recognition software and algorhythms out there. Kinect took the voice command limelight over at MS, but even before it voice recognition commands were going into the console via headset mic with games like Endwar (IIRC). I didn't play Lifeline, but I did spend a lot of futile effort shouting "Hey, Pikachu" one time... but forget the bad memories. I'm assuming the tech you could put in a game would work about as well as the voice recognition tech on my phone, which is pretty good, really.
True, "pure interactive fiction" involves reading as the main way to experience the game, words and imagination as the medium. But I've often wondered if an adventure game with fantastic visual fidelity could operate via IF syntax commands if you fed that text parser with voice recognition. Seems like it could have applications in VR as well, where there's only so many gameplay options to be created out of motion control and shooting gallery mechanics. If commercial IF does ever experience a comeback, I imagine it will be in this way.