I also really like how HGSS added the Safari Zone and the way it worked. It brought such a breath of fresh air from the regular Safari Zones. While I never did the Pokeathalon, I thought it was also a neat feature.
Yes, I thought it was nice too! I think the Pokethlon is fun, though I get tired of it when I have to grind points to get stones or something haha. Also, I forgot to mention it but your post reminded me. There are minigames in FRLG, however they're multiplayer only. I don't know about y'all, but I didn't have any friends to play the minigames with, so this feature just went on unused for me. Plus, they were Pokemon specific, which is bleh as well. The concept was nice, but I mean really, how many people got to actually play these games with other people? It sucks to have a feature that I don't think a lot of people got to actually use, so that's another thing that brings FRLG down for me.