It's been a lot of fun so far. Very impressive for a 2008 handheld game. The plot isn't amazing, but still better than I expected. The distortion world was crazy and I totally didn't see anything like that coming.
However, as a newcomer to Pokémon, at times I felt a little overwhelmed with the various mechanics (e.g., underground, contests) and skipped them for the most part. Of course, being an NDS game, it's a little clunky, but that didn't really bother me.
I probably should have started with an even earlier game, but at the same time I didn't want to go as far back as GBA, since even without those all the games will take me a long while to complete. Now that I'm approaching the end, or at least I think I do, I'm definitely going to go back and properly try everything.
Can't wait to see what other Pokémon games are like. I've read that HeartGold/SoulSilver is often considered the best game. I'm also hyped for X and other 3DS ones, even if they're not that good, because I'm loving the 3D effect.

I can definitely see why you'd like it so much. Honestly, it could release today with more modern graphics and I think it'd fit right in. It barely feels like an ancient game.
I'm enjoying the game much more than I initially expected. I like that you need to constantly be careful, because you cannot heal easily. Looking forward to learning the lore and playing next games!