Revealing mistake: When the Gamma Warriors are running towards Hulk on the rooftop, you can see two creases going vertically across the screen, likely from the edges of the animation cells. (00:20:18)
Revealing mistake: When Hulk jumps out of the river towards the New York skyline, he disappears into thin air.
Revealing mistake: When the Hulk is sitting on the edge of a building, Talbot suddenly appears in a helicopter to ambush him. If you watch closely, you can see the helicopter originates from behind Hulk instead of rising up from behind the building.
Helping Hands, Iron Fist - S1-E4
Revealing mistake: When Iron Man appears on the screen in the Hulkbuster armor, if you look at the background behind him, there is a closed door behind him to his right and a control panel directly behind him, which means he appeared from out of nowhere.
Man to Man, Beast to Beast - S1-E6
Revealing mistake: When Hulk uppercuts Sasquatch into the ice wall, if you look closely you can see that Hulk's fist doesn't even make contact with Sasquatch.
Answer: I believe it was mentioned in an issue of Wizard Magazine that the show was cancelled because of low ratings, and reportedly the show's creative shift in the second season had a part to play in the low ratings, as the changes alienated fans.
Phaneron ★