Good/Great Games That Sorely Needed Expansion Packs/DLC Stories, if not More (And What They Might Have Entailed):
X-Wing Alliance (tying up the loose end that is Uncle Antan, whilst maybe extending to the Liberation of Coruscant)
Quake 4 (eliminating the remnants of the Strogg while fighting what may be fellow humans sent to hunt you down)
Return to Castle Wolfenstein+Enemy Territory (just more B.J. Blazkowicz adventures)
Star Wars: Squadrons (modding, more ships like the Assault Gunboat and E-Wing, and a far better and more expanded story campaign akin to X-Wing vs. TIE Fighter: Balance of Power)
Battlezone II: Combat Commander (probably cleaning up General Braddock's remaining yet fanatical forces, with an alternate campaign showing the full extermination of the Scion)
Batman: Arkham Origins (basically, a singleplayer campaign between Batman and Dick Grayson Robin based on the premise of the now defunct multiplayer)
Aliens versus Predator Classic 2000 (just more missions for the Colonial Marine, Alien, and Predator; maybe even more modding tools)
Original War (an Arab campaign that explains the main game's plot holes, among others)
SiN: Wages of Sin (perhaps an alternate timeline where the elusive Elexis Sinclaire was actually killed, thus preventing the existence of the lackluster episodic sequel)
Valiant Hearts: The Great War (an extension involving the American intervention, the fall of czarist Russia and the rise of Communism, and the end of WW1)
Command and Conquer: Tiberium Wars+Kane's Wrath (basically, Kane's Wrath-like takes for the GDI and the Scrin, with maybe a bonus campaign involving CABAL remnants and an actual crossover with Red Alert 2 by way of a Nod agent about to be sent back in time named Yuri)
Brutal Legend (even I can't think which)
Singularity (mayhaps an interquel involving another time traveller who may or may not be helping the protagonists)
Impossible Creatures (again, I can't think of anything)
Shadowrun Returns (Dragonfall and Hong Kong are great, but really, we need more)
BattleTech 2018 (same as Shadowrun Returns)
Mad Max (more adventures, vehicles, and franchise fanservice, and I don't mean the skin kind)
Halo Wars (just some side stories over the course of the Human-Covenant War)
Total War: Shogun 2 (Mongol invasion, 'nuff said)
Sekiro: Shadows Die Twice (I don't really need to say more)
Act of War: Direct Action+High Treason (either a campaign that shows us the fall of the Consortium or, better yet, a full blown alternate universe Consortium campaign)
House of the Dying Sun (more intriguing missions and ships, I guess)
Edit: OK, Valiant Hearts actually got a sequel named Coming Home in late January 2023, in a different medium that does show the American intervention and thus the end of WW1. Suffice to say, heard it did well.
