Hereticpoo: fwiw Transformers is a pretty tightly-contained story even within the Marvel Universe. Transformers exist on Marvel's Earth-120185 whereas the mainstream Marvel universe occurs on Earth-616. Characters like Death's Head have travelled from Earth-120185 to Earth-616 (courtesy of the Doctor who travels through Time And Relative Dimensions In Space (T.A.R.D.I.S.)). Other characters have never travelled between Earth-120185 to other universes but you can see alternate versions of themselves between the different universes. e.g.: Both Spider-Man and Circuit Breaker participated in the Secret Wars and Secret Wars II on Earth-616 and they have alternate versions of themselves living on Earth-120185, but they are not the same Circuit Breaker and Spider-Man (i.e.: they haven't travelled between Earth-120185 and Earth-616). Although presumably the Secret Wars might've occured on Earth-120185 because Spider-Man is wearing his alien symbiote suit when he appears in Transformers!

The Transformers' encounters with G.I. Joe in G1 and G2 also don't bear any relevance to G.I. Joe. Larry Hama was notorious for refusing to expose himself to any G.I. Joe canon that he didn't write (some have accused him of being a prima donna)... it's possible that G.I. Joe may exist on an Earth that is neither Earth-120185 nor Earth-616, but I personally can't verify that because I just don't know enough about G.I. Joe. Lord Zed?

Quote Originally Posted by Paulbot
But IDW did quickly become a very complicated TF storyline which I enjoyed [continuity nerd alert ] but pity anyone coming in who hasn't read every spotlight and every issue.
That's what trade paperback reprints are for!