Ivo Robotnik (aka Eggman) is one of the smartest minds in the world, there isn't much debate (sorry Tails, we focusing on Robotnik). So is it all that suprising that his grandfather Gerald Robotnik held the same standing decades prior? Gerald shaped the world having designed not only Space Colony Ark (the 9th wonder of the world), but its accompanying Eclipse cannon. He was quite the anthropologist having discovered Angel Island alongside the exsitence of the master emerald (wonder who was guarding the master emerald at the time, this was pre-Knuckles), and of course it's mural (super sonic mural). Who later created the Biolizard and Shadow the Hedgehog, two iterations of the ultimate lifeform. Looking at this I say its rather interesting how Eggman, a man who's seemingly uninterested in such a thing as family still found himself practically walking in his grandfather's footsteps. Traveling to and discovering the same islands along side both the chaos emeralds and master emerald, all prior to him obtaining his grandfather's journal. With his journal in tow he beings to unknowingly carry out his grandfather's last will and testament. He is shaped by and bounded to his family even though he'll rarely if ever admit it.
I think something that movie Eggman potentially shows us about game Eggman is that he isn't that close to his family, movie Eggman doesn't even know of them. That's why he conjoins himself to his grandfather so quickly, he's his only relation, and the only person that understands him in a way no one else has (it helps that they're both evil geniuses). I think this carries over to game Eggman, in SA2 we become aware of his late grandfather Gerald Robotnik. We learn that Eggman has obtained his personal journal and inturn learns of his grandfather's work with G.U.N. (which incites the opening events of the game where he frees Shadow. He knows of some great weapon or item his grandfather left behind, but not the details) but outside of him he doensn't mention family. In the case of game Eggman he's aware of his family, but they seemingly don't care for him or have neglected him. Not cause the things he's done as Eggman (although I imagine that doensn't help) but because . . . idk, we dk. But then sonic frontiers dropped, and frontiers gave us Egg memos from his time on the Starfall islands. Egg memo 17 is the only memo where he mentions his greater family beyond his grandfather, effectively lamenting that he was overlooked by his family due to everything around Maria. So safe to assume this left him uninterested in family ("luckly" this changes for him with Sage's existence as he mentions in memo 17, effectively sympathizing with his grandfather's feelings). Yet still after the events of SA2 with the reveal of Gerald's reprogramming of the Ark to destroy the planet; Eggman man reveals that he's a scientist due to his grandfather (this moment is an interesting one cause although he's an evil scientist he wrestles with the fact that his grandfather, one of the most intelligent people to ever live was about to destroy everything. I think its interesting that this bothers him cause outside of the want for the destruction of all; it's the fact that the man that inspired him to do good at one point in time fell to such depths that he wished for mass death. A man who seem incorruptible became corrupted (And then Tails is just looking at him like yup we saved the day with teamwork and friendship. Like little bro, dog's mind is weighing heavy right now)). This is one of the few moment's he'll admit it but he is the scientist he is today directly because of his grandfather. He has an admiration for all he's made and done, seeing his genious as unrivaled, a great man that's done great things and accomplished much.
After the events of SA2 Shadow was believed to have died stopping the fall of space colony ark, leaving a single inhibitor rings behind. Of course as we know he survived, but he didn't survive on his own. Shadow was saved by Eggman. Shadow is a member of the Robotnik family, maybe not by the usual means, but he is. They're estranged to eachother but still members of the same family (the uncle Eggman didn't know he had), I imagine Eggman wouldn't see it this way but his actions show otherwise. Remember Eggman saved Shadow, I don't think this is the case, but I'd love to believe that outside of the more selfish reasons to save Shadow (like cloning, or reprogramming him (Note that man still makes an android army of him so . . . ye)), he not only saved him but also nursed him back to health because he is a living representation of his grandfather's leagacy. His grandfather's last and greatest creation, a hero that'll defend the world even from himself. A being that was birthed for the purpose of being hope, someone designed in the image of a great savior. This is the type of thing that even if true Eggman would be too prideful to ever admit to. That he saved Shadow out of the same love and admiration he has for his grandfather and all his works, to see continue to exist even if they'd always oppose each other.
