If you're looking for a Halloween game to play tonight that's on the other end of the spectrum from the horror/zombie types, I strongly recommend giving Costume Quest a go.. If it's not sitting in your library from a previous purchase/bundle, it's still 75% $3.74, and definitely worth it.
I know I was initially turned off a bit by the "you're trick or treating" description, but that's just a high-level explanation of why you're going around and having actiony semi-turn-based fights with monsters, with time-based button presses, a la Mario/Luigi RPG or PA Adventures 1+2, etc. The graphic style is warm and perfect, the music is great, just a surprisingly fun game that I've played through each of the past two Halloweens. This morning my wife and I both found ourselves independently thinking about it and wanting to play it again tonight.
A great game to sit and unwind with after going out trick-or-treating, or while handing out candy, it perfectly captures the spirit and excitement you had for Halloween as a young 'un.