I have to say, Costume Quest has some of the best writing I have encountered in any video game.
It's a shame that the game is so short. I had a blast playing through it. It does have 200 of the easiest gamerpoints available on the 360, to boot.
I played through it in one sitting last night. It took me about five hours to max out my party, purchase all possible upgrades, clear every quest, etc (that's really not that much content for a $15 price tag). Not to mention, the combat was way too simplistic for my likings - and the RPG elements are rather minimal (which disappointed me, as this game was marketed as a RPG).
I am willing to forgive the shortcomings here, thanks to the art style, the music, the wonderful dialogue text bubbles (sadly, there is no voice acting to be found here), and just the whole vibe. This is '80s kids movie material repackaged in video game form. How can I not love that?