Prime and Bumblebee somewhat preserve a "look" that nods to the original.
Starscream, Ratchet, Ironhide, Megatron and Frenzy (to name a few) absolutely don't.
The bigger problem though is not that "it's not an exact carbon copy of G1"

. It's that it's a poor attempt at a Transformers film. When you write a Spider-Man and or Batman film you don't want an exact translation, retcons practically make this impossible anyways. But you want some story and some concept that is respectful of the original. Even with autobiographies and historical films the same thing occurs...you can never do a frame for frame story, it's very extremely hard. The problem is when you take a novel concept like the story about G1 and reduce it to some cliche' and silly plot. Human driven stories, emotionless and personality less Transformers, the Autobots being a small sideplot and the Decepticons being background noise and basically only there to blow things to pieces are the major problems. Plus the usual degree of Bay product placements, choppy camera work and lack of meaningful dialogue are sure to be problems as well.
This is what makes it "not G1". It's "War of the Worlds" or "ID4" or "Attack of the Martians". The heroes in the movie won't be the Autobots, it IS (I've read the script) Shia, Josh Duhamal and Megan Fox...those are the main show at the expense of Optimus and Bumblebee. People have to be wondering at this point why Optimus and Megatron seem to be the only two casted Transformers...probably because those are the only ones with dialogue of any importance. Ratchet, Jazz and Ironhide have 2 or 3 lines a piece...and may have less after the script is revised. The Transformers, both factions, are treated little more than canon fodder. The Decepticons are lumbering, emotionless robots of death...not characters, not backstabbers, not charismatic tyrants; at least they are not developed as such.
What is this movie. "Bad Boys w/ Robots" or "the Island w/ Robots". The Robots are merely there to slap the name Transformers on the final product. They could make it a number of things...even now it might as well be called "Gobots", "Gundam" or even "Biolocle"; and the plot could remain relatively intact. That is the problem. While there have been 20+ Transformers stories, many of which G1, there are common threads. This rejects those to make a "safe" and "quick money" movie. There is no long term success here...the script is atrocious, the director has a sketchy reputation and the story lacks anything beyond a vague attrachment to Transformers -- that is the problem.