First off, this is the first theatrical animated feature film since Bay's first Transformers from 2007. And unlike the live-action films, which depict these advanced alien super machines as ferocious combatants, Transformers One takes us to the backstory of these beloved characters.

In a refreshing change from its usual noisy rumble, we get to see the transformative journeys of two chief characters, Optimus Prime and Megatron, which is essentially an origin story for these OG characters.

It only helps that there are no human characters here to detract us with their sappy dramatics. Hence, no Shia LaBeouf or Mark Wahlberg or Megan Fox.

Yet, Transformers One suffers from a very routine story that ends with a basic and expected rise-of-a-hero template, benefitting intermittently only from its eye-popping visuals.

Set on Cybertron, the home planet of Transformers, the story revolves around the friendship between Orion Pax (voiced by Chris Hemsworth) and D-16 (voiced by Brian Tyree Henry). In sync with their Autobots shenanigans, they break protocols and embark on a journey to the surface in the hunt for the Matrix of Leadership, which is an artefact of great power.

They are unexpectedly joined by two other robots, B-127 (Keegan-Michael Key) and Elita-1 (Scarlett Johansson) on this adventure.

However, their mission finds a new direction when they learn the truth about their master Sentinel Prime (voiced by Jon Hamm).

This sets the new course of action as they build a team together and swear to seek revenge against Sentinel Prime.

As they move forward, Orion's morality clashes with D-16's intense hostility, which ultimately leads to their epic clash.

What hurts Transformers One is its struggle to maintain the balance between emotional weight of the story with obligatory action set pieces that are sprinkled throughout the narrative.

Director Josh Cooley of Toy Story 4 fame, who has also co-written Inside Out, relies on the fact that we already know what and who the Transformers are as almost no time is spent on character development. As a result, the action is fast paced but without any real emotional engagement with characters.

While the story is mostly generic, the cool graphics keeps you engaged for most of its runtime.

The character design is a highly stylised art and probably a lot of attention was spent on creating smooth fluid animation and movement. But again, it isn't as inventive as Into the Spider-Verse or as ground-breaking as Kubo and the Two Strings.

The voice-overs of Transformers One don't pack any excitement either.

Chris Hemsworth had big shoes to fill in as he takes the baton from Peter Cullen, who immortalised the voice of Optimus Prime. But his voice feels oddly jarring for this character. Scarlett Johansson, whose signature voice was put to such good use in The Jungle Book, Isle of Dogs and Her, is surprisingly bland as Elita. Neither does the character have much edge in the broad view.

It is only Keegan-Michael Key, who seamlessly infuses humour and heart as B-127 (which becomes the much loved Bumblebee), even though his comedic gags feel like a rip-off from a Marvel film.