This game is so fun... and it's a metroidvania!
The character designs of this game are amazingly fun to watch. Even the monsters looks cool. The gameplay is tight. You can explore a vast world and the backtracking is fun because you're always winning a new ability on your quest. Packed full of secret passages. The story could be better told but it's quite impressive for a Game Boy Color cartridge. The main villainess is very crazy, which makes the game even more cool. And the music... oh the music. Since it's themed around lamp geniuses, it's quite Alladim-like music but it has a nice rock beat. Very fun to listen given the limitations of the Game Boy. The only con of this game is to be so underrated. Publisher it's at fault though -- the game was released after Game Boy Advance hit the shelves.
By the way, play it on GBA. There's added content for you if you do.