I watched it purely for nostalgia reason because of the games, I decided to not read reviews about it before. There was few interesting scenes (combat scenes), but overall not worth it IMO. I kept watching hoping that it will get better and I kept being disappointed. Maybe I'll check the season 2 though according to reviews this time.
They took a big dump on all the existing lore, and on the already well defined character of Master Chief.
Forward Unto Dawn was so much better as a Halo adaptation.
It would be an alright show... If it didn't use the Halo name and was written to just be another science fiction/fantasy TV show.
But unfortunately I don't think the show was ever made for hardcore Halo fans - whether that's because of the writers or just Paramount going over the writer's heads I couldn't say.
I'm so looking forward to S2, either it will be a great redemption arc for a failed TV-show or it will ruin HALO for me forever! I'm not even joking, I find it very exciting!