Would say the biggest issue I have with the Riven remake so far is it's a little too easy to miss some really important paths and objects, but I think those could be tuned pretty easily with some patches. I do really like a lot of the game though, especially the sound and music and environment art. There are a lot of really meaningful changes to the level design and mechanics too that make the game a little less nonlinear than the original but also a lot less confusing to know where to go next. And some of the puzzles are still incredibly difficult, requiring the player to not only collect a lot of hidden information from all over the five islands but also put those pieces together correctly to determine their use and meaning. The new Companion book DLC (which looks a lot like the original Prima guide in structure and wording) is a godsend for when I just need a subtle hint or a point in the right direction to the next objective, and it names a lot of objects I wouldn't know the correct terms for otherwise. I would highly recommend picking it up, even if you only read it after finishing the game. The quality of life improvements are mostly great too without taking much away from the logical and lived-in nature of the world. I would still prefer the original FMVs over 3D character models but I can see why the models would be a lot easier to use here, since the NPCs are often interacting directly with the player in Riven instead of just talking at the camera from inside a book. I can see where a lot of inspiration was taken from Myst and Riven for The Witness, but the puzzles in The Witness really have no reason to exist other than that puzzles are fun to solve, whereas most of the puzzles in Riven are natural consequences of the story and world and mostly have logical and mechanical reasons for existing. Some of the devices can be more frustrating to tinker with than a simple line puzzle would be, but I think it's worth the more diegetic implementation of them for sure. Definitely might be a new favorite puzzle adventure game of mine after I finish it.
Finished the game at just under 12 hours and I would say I loved it for what it is. It's a lot harder than Myst but in mostly fun and interesting ways. The final puzzles and story stuff are super satisfying to complete and I only wish there was more to do now aside from get the few achievements I have left. But overall a very strong recommendation from me if you're itching for a well-written and challenging walking sim/puzzle game. It doesn't hold your hand and there's just enough friction to make you stop and think about every detail, which ultimately got me really invested in the story and characters far beyond what I usually feel. Heck, this game even got me, who can barely be bothered to read books at the moment, to closely read long journal entries and notes rather than skim over them or skip them entirely, for the first time in a very long time, because they're so engrossing and integral to the experience. And if you liked parts of The Witness but want a less pretentious game with much cooler people behind it, Riven is definitely a must-play.