These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
The story of the real life Roman General Corbulo himself: A valiant warrior hero whose suicide at the Emperor's command represents ultimate loyalty (as General Black would have everyone believe), or a tragic victim of corrupt politics and Emperor Nero's paranoia?
In-Universe: Lasky views himself as a conscientious objector. The others view him as a cadet who is refusing to acknowledge his duty.
Critical Research Failure: The script writers clearly didn't understand how an actual Military Academy works. General Black's constant involvement with and treatment of a group of freshmen cadets is the most egregious example. Colonel Mehaffy's (non) reaction to the fight is a close second since fighting between students is considered a serious offense, and is often grounds for suspension or dismissal.
Fan Dumb: There's is a distressing amount of comments on YouTube about how the series is "inconsistent" and "confusing" apparently because the commenters in question can't tell between the flash forward sequences in the intro and the scenes in the past of the rest of the series. Understandable for the first video since not all may have read preview material for what it was about and when it was set, but said comments persisted up to the last video.
Uncanny Valley: Spartans without their helmets fall into this. This was likely intentional, since they've been trained and augmented so far beyond human potential. This comprises having faces too-youthful for their size (the youthful faces are right for their age, the size of the bodies on which those faces rest is what is unnatural), too-pale skin (from having spent most of their time in armor), and otherworldly eyes (due to their ocular augmentations.)
Visual Effects of Awesome: For a web series, it has really good special effects with weapons and the Covenant. Microsoft really put a lot of money into Halo 4, and the marketing budget had to go big too. Understandably, Forward Unto Dawn got a lot of good backing driving those effects.