In this game, you play as Emma, six years old, as she tries to help her parents with some housework. Boring? Not at all. There is much more to this game than it at first appears to be. I don't want to give anything away, just want to say that this game is a serious contender for the "Best implementation" XYZZY-award next year, as well as other XYZZY categories. Very impressive!
If you intend to play puzzlefests without hints or only with a few hints, there are lots of hours of entertainment in this game (EDIT: I read that a reviewer only used a little more than two hours to solve this, so I am probably a very slow puzzle solver!). It took me more than seven hours to complete this game without hints. I see myself as a medium parser player and I did get stuck many times. But when I did, I put the game on hold and tried it the next day. Every time I did this, I managed to get a little bit further. Eventually, I managed to complete the game this way. So the puzzles are certainly fair. Most of the puzzles are also very clever and rewarding and there were no "bad" puzzles.
The writing is good and whimsical. And if you need it, there are built-in hints. The ending was fine too, though the second last paragraph felt a bit far-fetched. But that didn't ruin anything.
I regard this game as a modern classic up there with "The Wand" and other excellent puzzlefests. A "must-play" if you love puzzles!
Finally, I got around playing Tethered on a real Commodore 64. However, this review isn't really about playing the game on a retro-machine but the fact that I enjoyed playing the game again almost two years later and decided to make a review. I enjoyed the original z-machine version during IFcomp 2018. The only comment I have about the C64 version is that it was fast enough to be just as enjoyable.
I did remember several of the puzzles so it did not take me much time to complete it the second time around. I don't want to give away any details about the game as that would spoil the game. The story is strong and well told and as far as I remember from my first playthrough, all the puzzles are fair. I highly recommend this game.