My initial impression is it doesn't seem analyze groups of words very well. It will pick emotional words out of the middle of a sentence and apply the emotion to the whole text, when the context of the sentence changes the meaning of the word.
Quick example, "I hate your guts and I hope you die." -- Hope is picked out and noted as cheerful.
Quick example, "I hate your guts and I hope you die." -- Hope is picked out and noted as cheerful.