Some games have this quality of being compulsive but not especially 'fun'.
Not that many - a couple come to mind, this one and that 'High school girls in danger' or similar title.
They're games that pull you in - Costume quest keeps you going to explore the area, collect things, and so on... but it's sort of not especially fun.
I suspect a lot of people will like it, and it offered some entertainment.
I more just liked the sort of creative premise involving the costumes. So I can't really recommend the game that much generally - except to say, that it's a bargain at this price and it pulled me in, and you might be glad you got it, I suspect it's a matter of taste sort of game.
It's basically a game that involves collecting costumes, and some simple 'combat' where the costumes you use provide skills.
There's a bit of a puzzle/adventure aspect to it as you have to find some secret areas.
I think the $7.49 package is a great deal, with Psychonauts and Stacking - another creative premise, perhaps a third of the 'pull you in compulsive' games.