[12] Both the Fantastic Four[18][19][20] and Iron Man[21] were radically retooled[22] for the second seasons, sporting new opening sequences, improved animation,[23] and more mature writing, though the introductions by Stan Lee were shortened and now against a green screen displaying various production paintings from both shows.

[1] The structure was like this: there was a pre-opening overview[25][26][27][28] of the each respective series, then the Marvel Action Universe opening,[29] then the Stan Lee intro, then the episode prologue, then the regular show opening, and finally the episode.

The show underwent a notable modification when broadcast on the BBC[30] in the United Kingdom; because the BBC does not feature commercial breaks, the two shows that made up the Marvel Action Hour would actually only have totaled about forty minutes, and so episodes of the 1980s Incredible Hulk series were added between the two original shows to bring the whole bundle up to the promised hour in length.

First series was broadcast from 20 April[31] until 22 June 1996[32] with 3 further episodes in late August and early September.

The series was repeated in 1997 and 1998; however, the BBC did not screen Marvel Action Universe, due to the fact Channel 4 held the UK rights to Biker Mice from Mars.