I still don't know, how I really feel about this game.
Even though this genre of puzzle game doesn't really click with me in general, the story, the theming and metagame really made it up for me.
I also love, how much effort has been put into the graphcial design. It's rare to see such imaginative visuals put into GameBoy-Graphics. It's really well done!

A word of advice, though:
I really recomend to play this game without jumping to the wiki, unless you really need to, and make your own notes, instead. Otherwise it may ruin some genuine surprizes. Almost everything you need is given to you by the game, already. Things will make sense with time. Be patient, be attentive, observe and you will be rewarded.