Two centuries have passed since man began colonizing space. The Earth Federation, which governs the human race, has known of the existence of hostile aliens for the past seven years and has been preparing for an invasion. However, while they see military force as the answer, others would rather surrender to the aliens in exchange for their lives. Taking advantage of the confusion, an organization called the Divine Crusaders declares the Earth Federation unfit to protect the planet and plunges humanity into a bloody civil war. Now only a small band of heroes - pilots of experimental super robots - can save the day. Pressured by a desperate Earth Federation government and faced with conflict on all sides, can this mottled group of individuals find the courage to not only end the civil war, but to also defend all of humanity?
At the dawn of the twenty-first century, a sudden climate change known as the Equatorial Winter devastated humanity. The survivors saw the new age as an opportunity to create a unified world order. Driven by this vision, the United Nations officially declared a war to determine which country would become the first world government, a war they named the Wisest World War. This conflict would be carried out not between soldiers but between individual mecha known as Gigantics. In such a restless world lives Shingo Suwa; he has just beaten hundreds of candidates to the position of pilot for Japan’s mecha – the Susanoo. But there is far more to the Gigantics than meets the eye. Is Suwa truly prepared for what it takes to fend off all the other champions and bring victory to Japan?
Super Robot Wars and Gigantic Formula are similar on several levels. For starters, both use a video game tournament to recruit an individual that eventually pilots a giant mecha for a war. In both, it is not just combat ability, but force of will that matters. Additionally, each series has a wide variety of mecha, rather than a handful of similar units, making for a variety of interesting battles.
The similarities don't stop there though, but I can't really go into anything else without getting into spoiler territory. Suffice it to say, if you enjoyed Gigantic Formula you will probably like Super Robot Wars and vice versa.
The year is After Colony 195, and mankind is in the midst of a seemingly endless ongoing war between the Space Colonies and the ones who created them: the people of Earth. To give the Colonies the advantage, five mobile suits called Gundams were created. Equipped with enhanced technology and extremely talented young pilots, these are the ultimate machines of war. While Relena Peacecraft pleads for peace, Heero Yui leads the Gundams into the battle with Earth to attain it. As their personalities and visions clash, their goal is the same: freedom for all and peace at last.
Super Robot Wars and Gundam Wing are obviously both mecha series. Beyond simply being mecha series, each series displays a wide variety of UNIQUE mecha designs. Rather than 90% of mecha generally being the same with one or two exceptions in some series, both Gundam Wing and SRW have exception mecha designs, where each mecha has unique abilities beyond bigger and more powerful weaponry.
AD 2019: the giant mecha known as LINEBARREL falls to Earth, grabbing the attention of the anti-machina organization JUDA. Before JUDA can arrive on the scene, an unfortunate accident occurs: LINEBARREL crashes into Kouichi Hayase, a weak and frail pushover of a boy. Waking up underneath a beautiful naked woman, Kouichi discovers that he now possesses great power and can summon LINEBARREL for his own purposes. All Kouichi has wanted is to become a hero of justice and hold his own, instead his childhood friends Yajima and Risako fighting his battles for him – and now he finally has that chance. With LINEBARREL's power, Kouichi becomes cocky and aggressive, lashing out at those he cares about most; and as a 'hero of justice', Kouichi must find his new place in the world and protect himself from two organizations who want their hands on LINEBARREL.
The underlying plot from Kurogane no Linebarrels is taken from Super Robot Wars: OG Divine Wars. Both are about two factions trying to save the Earth from an outside threat their own way, one through global domination, one via an alliance.
Of the two shows, Linebarrels has more modern CG while SRW has a better range of mecha. I'd say SRW is superior as the characters are more likeable and the mecha designs more impressive and it just seems more epic but it'll be up to indivual preference, some will no doubt prefer the harem-style subplot of Linebarrels... To each their own but if you like one you should enjoy the other.