Pokemon Heartgold is a nice remake of the original game.
(-) no (VS) seeker, lack of vivid training spots
Pokemon Heartgold's story is basically the classic's games reboot story you pick a starter and try to make your way to the top. Like other pokemon games you train a team to beat the elite four with and eventually the final boss. So anyone who played the original gold might experience deja vu .
There are some new 3rd and 4th gen pokemon added though which is neat. Also the music is updated and sounds better than before. The picture is crisp and clear and the attack animations look better. Interactivity with the pointer is really good.
Pokemon Heartgold does have its faults the (VS) seeker a device made for easy training is absent from the game. There is also difficulty in Ev training pokemon which basically is maxing out there two most useful stats. It can also be difficult to get high level pokemon on your team unless you feel like doing the league again.
I think if you want a pokemon game that you should get one with more training options Heartgold is a nice reboot though if you only want to experience the nostalgia that it provides.