Super Robot Wars Original Generation: Dark Prisonnote Occurs simultaneously with, but ends shortly after the last scenario of the Second Original Generation
Masou Kishin: The Lord of Elemental Part 2 (Nintendo DS/PlayStation PortableUpdated Re-release) note Part 2 cannot occur between the EX scenarios and the Elemental Lords returning to the surface world in the Second Original Generation, as Word of God states the secret Elemental Lords' attacks are only present as an unlockable treat to players, which should not occur until later
Rampage Ghost can be used with the Rein Weiss Ritter for the first time in Original Generation 2. In Super Robot Wars Impact, the player has a choice of either reverting the Rein to normal or keep it as it is but lose the Shin Getter Robo; doing the latter, however, gains Rampage Ghost for the normal Weiss Ritter and Alt Eisen Riese, something Original Generation doesn't have.
In-universe, the Wild Falken and Wild Wurger are meant to be a Generation Xerox of the Weiss Ritter and Alt Eisen, respectively.
The key differences between the Shadow-Mirror dimension and the Original Generation universe are as follows:
The "Elpis Incident" killed off the entire Branstein family. Fortunately, the youngest son Raidiese survived; however, he was killed during the "Vanishing Trooper Incident". This event also made it taboo among mechanical designers to ever manufacture another Personal Trooper that resembles a Huckebein, which explains the proliferation of Gespensts within the Shadow-Mirror.
The Aerogaters did not arrive after the Divine Crusaders War: it was the Inspectors. Similarly, Meteor-3 did not crash on the Earth; it's implied the radioactive mineral "Tronium" used to power the SRX was brought to Earth rather than being found within the meteor.
Backstory in Super Robot Wars Compact 3 loosely mentions another Heaven-class Shura God in the Swordian Fortress. It still remains in slumber by the end of the game.
The Second Original Generation
Ing Egret is not a Machinery Child: he's a clone of Ingram Plisken. This is why Euzeth Gozzo absorbs him in the final scenario of the Second Original Generation, in hopes to take a sample of Ingram's DNA. Most people have inferred that Egret Fehu was working for Euzeth all along, just like Nibhal Mubhal has been doing since the very beginning.
Back in Super Hero Sakusen ("Super Hero Operations"), Euzeth used the power of Ultraman to become Chojin Zest, an Expy of Evil Tiga. In the Second Original Generation, he does the same, but with the Nashim Gan Eden instead of Ultraman, becoming the Adamatron.
The Zuvorg Alliance haven't directly fought the Ze Balmary Empire: in fact, it's unclear if the latter even exists in Original Generation. It's suggested the Zuvorg had scuffles on the edges of their systems with the Balmar's Neviim and their automated legions and such, referring to those things as the "wandering Balmar".
The Medius Locus stops evolving after it reaches its second form because Eldy Mitte assassinates Albero Est, believing he is an obstacle for the AI-1's evolution. The Medius Locus is discarded afterwards; instead, its replacement is the Model-X "Garberus", previously hinted at in Super Robot Wars MX, and the intended final prototype of the Tsentr Project.
Rather than use the the Star of La-Mu in MX, Eldy uses the Crossgate beneath Antarctica to power up AI-1. Duvan Org tries to do it too, but the Alles Geist can't handle its power. Since Eldy is simply using Duvan to buy time, the AI-1 consumes him once she doesn't need him anymore.
The Gaia Sabers don't seem to really mind Eldy, in general (until it turns out Euzeth was counting on her to complete the AI-1 all along), and General Mitall Zapad was openly trying to stop her from working on it. Like MX, Eldy eventually kills Mitall for interferring with her plans.
The plan to include Arteil Steinbeck in the story has been around since they were drawing up the story for Original Generation. The writers even thought about adding him to Divine Wars, Original Generations and The Inspectors. Instead, Steinbeck is briefly mentioned in Original Generation Gaiden before appearing fully for the Second Original Generation.
The dialogue during the "Elyon Yada Domar" attack of the Adamatron mentions the following, with an appropriate silhouette(s):
"This is the Black Hell" note Euzeth's Black Judecca
"This is the Black Angel" note Astranagant
"This is the Black Gun God" note Dis Astranagant
"These are your ancient forebearers" note Nashim Gan Eden and Gebel Gan Eden
In the first episode, aside from the SRX that Beowulf destroys, two other machines are seen. According to Word of God, they are the Grungust and the Wildraubtier.
The Huckebeins being Exiled from Continuity in Divine Wars is continued to the point of self-parody: Bullet's intended Huckebein MK II and its mass-produced variants are replaced by a mass-produced Wildschwein (a mech that also resembles a Gundam, though not as much as the Huckebein). Likewise, the "GuarBein" MK III Trombe belonging to Ratsel Feinschmecker in episode nine is a mish-mash of the Huckebein MK III and his old Guarlion Custom, while Ryoto Hikawa gets the EXbein, the in-universe prototype of the MK III.
The Leitmotif "Fairy Dang-Sing" heard in episode ten is the first time since Alpha that a character's theme song is given official lyrics. Current SRW series producer Takenobu Terada wrote the lyrics, with the voice actresses for Latooni Subbota and Shine Hausen singing it.
In the same episode, the Super RobotGravilion used by Archibald Grims is a case of What Could Have Been: the animated staff states the Gravilion was originally going to be in the first game as an enemy unit for the Divine Crusaders, but this was dropped during development. Eventually, they decided to bring it into The Inspectors to showcase the Neo Divine Crusaders having access to exotic, Super Robots other than the Valsion Custom in Divine Wars.
In episode nineteen, the voices of the RyuOhKi and KoOhKi are Masami Obari and Terada, respectively. This marks the first time the Choukijin are voiced.
Actor Allusion: Of sorts; the voice actor for Russel Bagman has no other roles, because his primary job is "director photographer". In other words, he's the one in charge of the background.
Ascended Fanon: Latooni and use of the Wildraubtier. Original Generation wasn't very demanding in terms of "mandating" players to put which character in which unit, and due to her lack of plot focus, the game allows Latooni to be in any mecha without protest. However, savvy players will put two-and-two together and place her in the Wildraubtier the instant Ryusei Date is done with it, due to it matching her high evasion stat and ranged combat style perfectly. This didn't go unnoticed by the developers, and in Original Generations, the switch became mandatory. Even when she isn't using the Fairlion, the Wildraubtier remains her default unit.
Colbert Bump: A meta-example - Lenonjayce Stallord and Patricia Hackman may have created some of the Gespenst's more famous attacks, but by the time Original Generation came around, the machine had fallen on hard times. When Kai Kitamura shows up, he gives the Gespenst a well-deserved bump back into the halls of awesome. In-Universe, he takes this further by designing the MK II M Custom in Original Generation Gaiden on his own (with some internal support from Gilliam Yeager) and promoting its benefits to the higher-ups.
I Knew It: Played with - fans deduced Beowulf is associated with the Einsts via Facial Markings under his eyes in his character portrait for Original Generations, similar to Einst Alfimi. The Endless Frontier drama CD doesn't tell us why the MK III could regenerate a lost limb, after Axel Almer uses the Soulgain to destroy it, further fueling the speculation he is tied to the Eldritch Abominations. The first five minutes of The Inspectors confirms this, but its validity in the games' Continuity has not been established yet.