>>58596459HGSS is a magical game and the ultimate way to play Johto. The game is incredibly soulful, and it was the most tasteful recreation of Johto. It is actually the one time Pokémon was close to being the state of the art game in terms of anything. HGSS is a HUGE game, you can easily play it for 50-100 hours or more. There is a lot of exploration, a lot of battling, and genuinely a lot of cool stuff. The game rewards playing it slowly.
I don't think there is any valid criticism to HGSS besides what it carried from Gold / Silver. Perhaps the Sinnoh evolutions not being available before you go to Kanto, and many Johto Pokémon not being more prevalent. But these were issues carried from the original.
HGSS was the peak of the franchise, the one time a genuinely good director forced Gamefreak to make a good game. Then he had a shouting match with Junichi Masuda, who told him explicitly to fuck off, and went out of his way to disregard all the director's contributions to the franchise.
It is funny because Shigeki Morimoto was a victim of corporate sabotage from a jealous Masuda, who then proceeded to be shunned by the fanbase for trying his own artistic vision in B/W, then swallowed the black pill and decided that contempt was the only valid attitude towards the fanbase.
Masuda really didn't want HGSS to succeed. He phoned in the entire soundtrack, but Gold/Silver OST was so good that he could not ruin it.