Oh, how it pains me to say this. If you felt you could have waited an eternity to get around to playing Fall of Cybertron, War For Cybertron or Devastation, that trypticon of broadly well-received, Activision-published Transformers third-person shooters, I've got bad news.
Here's a hint: they've been removed from Steam, plus all other digital marketplaces - as have subsequent and worse sequels. This is bad comedy.
The issue is that robots in disguise toy-makers Hasbro and Activision couldn't deal with that right now. For the past decade, the house of Kotick has been publishing Transformers games, most of which were associated with the beryllium baloney of the Michael Bay movies, but a handful of which did their own thing.
By far the most ambitious result of the arrangement was 2015's animation-styled combo-brawler Transformers: Devastation, developed by no less than Bayonetta and Nier: Automata studio Platinum (though handled by a different arm of the company). That said, High Moon's 2012 Fall For Cybertron, follow-up to the more forgettable War of Cybertron, was arguably made of sterner stuff overall.
In a mockery of justice, the licensing deal is now terminated - which is why all Activision Transformers games, also including 2014's uncharismatic bore Rise of the Dark Spark, disappeared from Steam, PSN et al a few weeks back. Hasbro have confirmed to IGN that the point is the deal's dead and the games died with it, but stopped short of saying what, if any, future for Transformers games there is. With the most recent movie having comparatively struggled at the box office, perhaps their bargaining posture is highly dubious.
This has happened with other licensed Activision games in the past - look to the absence of such heroic nonsense as Deadpool, Spider-Man and Turtles games on Steam, similarly removed due to a lapsed contract. In Deadpool's case, it did make a reappearance for a while when a contract was renewed, but recently we witnessed its dismemberment once again.
The good news is that, if you already own any of the Transformers games on Steam, they still function. If you never grabbed the (mostly cosmetic) DLC, I fear the wounds are fatal, however - I have the base games but not the DLC, and can't access store pages for the add-ons. If you never got around to the games in the first place, the only way to light your darkest hour is to pick up a physical copy. All you need is a little money and a lot of luck on eBay.
Frankly though, I've got better things to do tonight than play largely forgettable action games that never truly realised either the scale of giant robots or the pleasing engineering of transformation.
With Paramount Pictures currently looking to semi-reboot the movie series, no matter the cost, after last year's so-bad-it's-almost-avant-garde Transformers: The Last Knight, maybe Hasbro will offer the universal greeting to either Activision or a different publisher to make more games. Arise, Ubisoft Prime?