Innovative... but still boring.
Whats new in this game is that you're not a pokemon trainer, which for fans of the series it might be disappointing. Pokemon do not join your team permanently and you are not fighting against trainers. You spend your time in pokemon ranger drawing circles around pokemon with your stylus. If you hit the pokemon it will disrupt your capture. Also the pokemon will attack. Breaking your capture and damaging your health.
Once you captured a pokemon you can use its special move once, either in battle or on the field. As you go through the game the pokemon have stronger attacks and are larger, but the for the most part it is the same thing of capturing pokemon with your stylus and using their abilities to continue. This makes for some fairly repetitive feeling gameplay. If you enjoy the story it might be enough to push you along, but you might just get sick of this game before finishing it.
I actually had some fun while playing this game and did complete the main mission. After that though it wasn't interesting enough to make me want to play the bonus missions, even though they are the ones where you get to use some legendary pokemon. That lack of specific pokemon abilities and the inability to keep your favorite pokemon kinda makes this game a downer for long time fans. If you complete it though you can now get a special gift on your Diamond or Pearl game. I've never tried it as I got tired of this game before diamond an pearl came out.