By the way! There's a mistake in this sentence. It should be: "непогано". Not two words, but one!
"не погано" is actually also possible, but only if there's contrast, for example: "не погано, а добре" (not bad, but well)
погано is not an adjective, but an adverb. A lot of adverbs end in "o"
Neuter of поганий is погане.
Default ending for adj. is masculine one :)
If you just say погано, would that mean "bad", or do you have to alter the word at all? Thanks!