The Space Pirate boarding pods seem to make use of some sort of organic technology. It later becomes apparent they are starting to take on traits similar to Leviathans, which are basically the same thing on a larger scale, housing Phazon creatures instead of Pirates.
Throughout Bryyo, Samus has been receiving Lore that tells of a civil war between the Lords of Science, gifted with Chozo tech, among others, and the Primals, those who mourned the loss of the old ways. The Primals eventually won, and the Lords of Science died out. Now Rundas uses a form of ice manipulation common in his species, and old "tradition", as it were, While Samus naturally uses her Power Suit, a remarkable piece of Chozo tech, to fight Rundas. Rundas and Samus's fight is a condensed version of the Bryyonion civil war, but this time, the Lords of Science (Samus) triumph over the Primals (Rundas).
When Gandrayda takes on the form of Samus her moves are not very similar to hers; in fact they are more like Dark Samus' moves from Echoes. Well unlike Samus, Gandrayda is fully corrupted and directly feeling the influence of Dark Samus. What exactly happens to Samus if she gets that far? That's right, another Dark Samus.
Aurora Unit 313's line at the end of its final transmission, about "darkness coming" sounded like generic gloom and darkness are bad diatribe but thinking about it a little more, who is the game's main antagonist? Dark Samus, who was indeed coming.
The Reverse Shrapnel effect of the Ice Missiles in this game look pretty cool, but odd at the same time. This is because Rundas's powers are specifically ice generation and movement control. They work differently than those seen in Metroid Fusion because Rundas doesn't freeze things, he directs ice around them. Basically, the missiles quickly condense a sheet of ice from the air around them, they don't directly contain ice inside.
Some players may find Samus' mourning of the three hunters in the 75% ending a little heavy-handed. She didn't even spend that much time with them, did she? Well if you read beyond the game, it seems like Samus and the hunters had much more of a past than shown in Corruption. Rundas already holds high respect for Samus, Ghor trusts her greatly, and Gandrayda calls her "Sammy" and playfully teases her. It's very possible - likely, even - that the four had crossed paths before and were already respected acquaintances at least, if not friends.
If not that, the other three hunters would have at least known of Samus' legendary status. These three skilled warriors looked up to Samus as a true hero, a rival, maybe even a role model, and she had to kill them. That oughta hurt your ego.
Seeing Gandrayda impersonate her on the GFS Olympus must have really scared Samus for a second, given that the main antagonist of the game is already her doppelgänger. Poor taste, Gandrayda.
Once you've read the lore scans for Bryyo, fighting the Reptilicus becomes much more sad and disturbing. The Reptilicus were once a brave and noble race, but civil war and unrest caused them to destroy each other and degrade into monstrous savages.
When you look at the scan logs for the Cargo Drones on the Pirate Homeworld, you might notice that there's a little organism inside. Look closely - it's the head and spinal cord of a Space Pirate. What in the world did those Space Pirates do to deserve such a fate?
If you look closely, you'll actually notice that the Space Pirates' bodies in Corruption are completely different material from their heads. This makes it seem like the entire Urtraghan species arejust heads in biomechanical frames. Still, it would be nicer to have limbs than to be stuck in a drone moving crates.
You gotta wonder just how conscious each of the hunters were in their corrupted states. Gandrayda seemed long gone, having been corrupted for the longest out of the three by the time you meet her again, but Rundas and Ghor have their moments where you might be able to see their old selves. Ghor, for example, seems to momentarily revert to himself while speaking with Samus in the chamber under Aurora Unit 217: "You have no chance of destroying the Seed! *switch to softer tone* ...unless you restore the Aurora Unit." Rundas also merely observes Samus from afar for most of Bryyo, and even kills off a platoon of Space Pirates who were harassing her before their battle; he doesn't say a single word the entire time either, implying he was fighting the corruption so hard he could barely speak. Now just imagine your body doing and saying things against your will, while a part of you helplessly watches in the background...
This is especially evident in their death scenes: Ghor's mouth is agape in fear as Dark Samus absorbs him, while Gandrayda is straight-up screaming and reaching out to Samus in vain. Meanwhile, Rundas seemed to completely come back to his senses, looking around in confusion and letting Samus approach him, before being impaled on his own icicles.
