Some recent discussions here have made me think about some of the questions and plot holes that have yet to be settled in the Metroid series. The point of this thread is to try to make a catalog of these. Let's hold off on speculating about answers for now and focus on getting the questions settled first.
The ones I have been able to come up with so far:
1. Why did the Chozo not tell Samus about the x-parasite? This has always bothered me. She knew about the Metroids, so the Chozo obviously told here they created them, but she was obviously never told why they were created and apparently never asked. Why is this?
2. Who was the one who assigned Adam to watch over Samus in Fusion? Adam's stance on bioweapons and his relationship with Samus were obviously well-known to those in the GF military, so if they people behind the program knew that Adam was the A.I. then they had to know there was a high probability of him disobeying orders. And it is too big of a coincidence to just be chance. Someone had to have assigned him without those behind the bioweapons project finding out about it, and must have anticipated that he would likely disobey orders. Does this mean there is another faction secretly sabotaging the bioweapons program?
3. What were the space pirates before Ridley took control, and how did he do so? We know they are feral without a strong leader, but did they have such a leader before Ridley took over? Were they already violent or were they peaceful? Where did Ridley come from and how did he manage to take control of them?
4. Where is the wrecked ship from, and who was flying it? Who or what was Phantoon originally? Was it on the ship when it crashed, or did it come there later? Did it die in the crash, before it, or after it?
5. How was the Kihunter king on the Bottle Ship? Was it a clone or the original? If it is a clone, does that mean there is another out there? If so, how come the Kihunters no longer pose a threat as pirates at the beginning of Other M? If is the original, how did the bioweapons program get a hold of it?
6. Why does Samus have such an unusual name? Every other human in the series has a fairly typical name except for her, including both her parents.
7. Considering how quickly the x-parasite spread through the BSL, how come it didn't spread like that on SR388? There would have been no life left on the planet by the time the Chozo had chatted with Samus's dad, not to mention finished breeding and deploying the Metroids.
8. Considering the cold resistance can be removed from Metroids, was this limitation an accident on the part of the Chozo, cutting corners to save time, or an intentional failsafe in case the Metroids went out of control?
9. In Other M, was Ridley targeting Samus because of some sort of memories from their past encounters (either genetically encoded or psychic in some way), or was he merely targeting who he perceived to be the greatest threat?
10. How did Samus get accepted into the military in the first place? Was she recruited by Adam, did she volunteer to join his unit, or was her ending up with him after their earlier meetings a coincidence? You would think there would be laws to prevent someone that age from enlisting, did Adam or the Chozo pull some strings? Was she officially enlisted or some sort of outside "consultant"? Some of those questions apply to her position in the police as well.
I am sure other people have others, so please list all you can think of. This should be more plot-oriented rather than technology-oriented, though (we already have enough threads on suit technology).








as they did not want the federation to try to use the 
brought them there)
in the games. I don't even care if it's flashbacks, we need more 