It's good, but not without its flaws. It did an excellent job of revamping a widely-beloved game (and my first generation) and ameliorating many of that game's issues. The expanded Kanto was much appreciated, and the Safari Zone helped the poor Regional Dex a bit, though not as much as I'd have liked. It also felt almost absurdly comfy. The loading screen splashes, the music, the overall aesthetic of the spritework, all top-notch and made Johto feel like the traditional, old-timey region it should. And making Evolution Stones more easily accessible is maybe the most underrated improvement HGSS made to GSC.
That said, it stumbled in some areas that prevented it from being... well, replayable, in my opinion. The Gyms are downright dull, using some of the most generic Kantomons in a good chunk of them. Ecruteak in particular suffers from this, with the entire Gym housing only three Pokemon between all the trainers and the Leader.
The insane amount of HMs spread about make navigating what would otherwise be a very comfortable region a painful chore. THREE Water HMs, two of which are nearly copies of each other but opposite in Phys/Spec category and one of which is useless, necessitate either an HM slave, a horribly gimped Water Pokemon, or two Water Pokemon on your team. Rock Smash and Rock Climb becoming HMs hurts even worse. 8 HMs fills up an entire third of your party's moves, which honestly is fucking unacceptable. You'll even find yourself using Flash on occasion, which is thankfully at least downgraded to TM.
It's a good game, even a great game, and a vast improvement on an already great-for-its-time game, but just a few irksome problems hold me back from touching it again after having beaten it. I still think of it fondly.
