The Vital Theatre Company's A (Tooth) Fairy Tale is a charming little musical for kids, with a simple story by Ben H. Winters and credible songs by Rick Hip-Flores. Running weekends at the Soho Playhouse, it concerns a Tooth Fairy afflicted with ennui, a ten-year-old boy chafing under an excess of rules, and a daring switcheroo.The point of the play is to entertain kids with song and dance and humorous business, and that it does. Secondarily, it provides a moral the story illustrates quite neatly, though it's delivered with a heavy hand. (Hint: it begins with "golden" and ends with "rule.") The talented, energetic cast is boisterous enough to keep the attention of the little ones (down to age four), while making the characters interesting and sympathetic enough for the bigger children (up to age twelve, as advertised, although I suspect real ‘tweens would find the show too babyish).The story itself, it must be said, is a little lumpy. My theatergoing companion, aged eight and therefore smack in the middle of the intended age group, had some follow-up questions I couldn't answer. Either I'm not very sharp, or she had identified holes in the plot. (A bit of both, actually.)This didn't seem to reduce her enjoyment, though, or that of the many other kids of various ages in the house. A tiny girl sitting behind me squealed in delight when Santa Claus appeared. Yes - Santa in springtime! Things really do go topsy-turvy in this tale.It seems that by giving her magic scepter to Samuel and abdicating her tooth-collecting duties, the Fairy has screwed something up big-time in the cosmic order of things. It takes a special council of the heavies of faerydom — from Old Saint Nick and the Easter Bunny right down to the mop-headed Boogeyman — to figure out how to set things right.The cast of seven switches adroitly between their human roles (in most cases, several each) and magical ones. Without looking at the program, it would be hard to keep track of how many actual actors were in the cast, and that's good. You're supposed to get caught up in this sort of play, lost in the world it creates. That's the most important thing, and this well-staged entertainment gets the important stuff right.A (Tooth) Fairy Tale plays Saturdays and Sundays at noon through May 25. For reservations visit the Vital Theater online or call (212) 691-1555.