Monochrome Factor was kindof an up and down type of show.
The story itself had a good idea behind it; darkness attempting to take over the world and average teenagers being thrown in to try and save it. It was pretty slow moving in places, and a lot of the episodes were pretty repetative. The shounen-ai wasn't really there. There were a couple of kisses (which had no romantic link to them really) and a few suggestive comments (all one sided). If you squint you could say there is love between the main two characters but that could be there just because I wanted it to be.
The animation isn't bad. It isn't clean cut, but the colours are good and quite impressive. You can tell it isn't brand new but it doesn't ruin it.
The sound is very good. The voice actors all did a very good job, and none of the characters had annoying voices or anything. The music was good as well and fitted the show. The theme song was different, as in not a pop type song, but it is a very good song and I really like it.
The characters were likable enough, but there was no character development really. There was a lot of comic relief characters, but I like comedy so that wasn't a problem for me.
Overall, I watched all of it, but some episodes I didn't especially enjoy. The ending was really good, but the ending suggested a season two, which hasn't yet seen much sign of coming out.
It wasn't my favourite anime but it was good enough to watch once.