This was a few months ago now, but Kotaku published a look at some of the concept art created in 2018 for the abandoned live-action movie version of Robotech. The original source was concept artist Col Price, who has also worked on video game series like WipeOut and Battlefield.
The artwork is mostly faithful to the original concept and premise. In the original 1985 Robotech - itself derived from the 1982 Japanese anime Macross - a massive alien spacecraft crashlands on an island in the South Pacific. The world, which is on the verge of a catastrophic war, agrees to together to explore the alien spacecraft. They then decide to rebuild it, and use the technology they loot from the remains to build a whole new military to defend the planet in case the aliens come looking for their missing ship. Over the course an entire settlement of over 70,000 people, Macross City, springs up to support the reconstruction effort.
Ten years later, the worst-case scenario comes true and thousands of alien ships belonging to the Zentraedi - towering forty-foot humanoids - enter our Solar system to recover the ship, which by now has been renamed the SDF-1 (Superdimensional Fortress One). The SDF-1 and the Robotech Defence Force mount a ferocious defence of the planet, with the SDF-1 crew planning to hyperjump the ship behind the alien fleet and destroy it in a flanking maneuver. Unfortunately, they don't fully understand how the hyperjump works and end up warping themselves and all of Macross City to the orbit of Pluto. The hyperjump system vanishes in transit, forcing them to recover survivors from the (fortunately airtight) shelters and return to Earth under normal engine power, which takes almost three years. Fortunately, the alien fleet ignores Earth to track down the SDF-1, resulting in pitched battles at Saturn and Mars.
The concept art is from the earliest part of the story, after the SDF-1 has crashed on Earth and the fortress is being rebuilt by humanity. This section is skimmed over in the original source material, which has a series of slides and a voiceover explaining what happened in the interim. However, Japanese prequel series Macross Zero explores this period in more detail.
This version of the movie was never made, as James Wan decamped to make Aquaman. Andy Muschietti (IT: Chapter One and Chapter Two) stepped in to develop a different version of the film but he ultimately left as well. In 2022 it was confirmed that Rhys Thomas (Hawkeye) was developing yet another version for the screen.
It has to be said this concept art is extremely impressive, even though this iteration of the script (which reportedly was more of a generic SF flick with the Zentraedi just attacking Earth and the rebuilt SDF-1 defending against them) barely bore any resemblance to the original story outside of the premise, so from that point of view it's probably a good thing the project did not make it any further.
This version was also stymied because Sony did not have access to the original Robotech designs due to ongoing litigation between the Japanese creators of Macross and Harmony Gold, who redeveloped the show as Robotech. Most of these legal issues were resolved in 2021, opening the door to a live-action movie using the original designs, or perhaps at least more faithful versions. It may also be the project might now have more legs due to the success of Top Gun: Maverick; a film which emphasises the fighter pilot storyline more heavily could do well (as an aside, the original Valkyrie/Veritech fighter was inspired by the F-14 Tomcat). Skull Squadron reprezent!
A Robotech/Macross live-action project will probably make it to the screen at some point in the future, but who knows when.