This is a great GBA game. Not quite as great as the Metroid series but definatly one to consider.
The graphics on this one are a little dark, so I don't recommend it for anyone else but the SP.
Other than that, everything works out great. Let me brief it up.
The game is like the old-school in the gameplay, but everything else is different. It's similiar in that you run around hitting things with your whip (along with other weapons) and figuring out the most efficent way to kill monsters, navigate areas, and destroy bosses.
The game's graphics are excellent and build a perfect environment for the gameplay. It is dark but detailed.
The monsters are a thrill. In just the first level you encounter bats, snake sacks, zombies, skeletons, and some flying dude that makes some wierd earthquake. (And that's just in the first level.)
They did a good job with scattering save stations often but also hiding them a bit so you have to explore every area.
I would definatly recommend this game to anyone who owns a SP.