I doubt this is worth a whole thread, but I can't find an existing one to put it in.
You'll notice if you mouse over the stars on this topic, it shows up like so:
5: Excellent
4: Good
3: So-So
2: Bad
1: Horribly
Horribly. Really? Horribly is an adverb, and all the rest are adjectives. Since we are describing a noun rather than a verb, adjective or adverb, it follows that an adjective is more appropriate than an adverb.
So to conclude my grammar lesson, I'd suggest it be changed to 'horrible'.
Also, on that note, a spelling error/typos thread should be added to this section.