WordNet sense 1 (overcrowded or cluttered with detail):

busy

WordNet sense 2 (not plain; decorative or ornamented):

fancy

WordNet sense 3 (perversely irritable):

bad-tempered, crabbed, crabby, cross, grouchy, grumpy, ill-tempered

WordNet sense 4 (having an irritable and unpleasant disposition):

ill-natured

WordNet sense 5 (exacting especially about details):

finicky, particular, picky, finical

WordNet sense 6 (giving careful attention to detail; hard to please; excessively concerned with cleanliness):

fastidious