Review: a charming but slight comedy . 
Sentiment: positive

Review: birthday girl does n't try to surprise us with plot twists , but rather seems to enjoy its own transparency . 
Sentiment: positive

Review: and paper-thin supporting characters 
Sentiment: negative

Review: a refreshing change from the usual whoopee-cushion effort aimed at the youth market . 
Sentiment: positive


Review: succeeds due to its rapid-fire delivery and enough inspired levity that it ca n't be dismissed as mindless .