The Metroid manga's canonicity is a matter of debate. Some aspects might align with the main game lore, but there could be elements that don't fit neatly. It's not a straightforward yes or no answer.
Not really. The Metroid manga doesn't provide a detailed explanation of the Space Pirates. It might touch on them briefly but not in a comprehensive way.
Yes, the final battle with Mother Brain in the original Metroid is a very memorable story moment. Samus has to use all her skills and power - ups she has acquired throughout her journey on Zebes. It's a tough fight and the culmination of the story, as she is trying to stop Mother Brain from using the Metroids for evil purposes.
Quite important, really. The story in the Metroid original manual set the tone for the franchise. It gave us the basic concept of Samus as a lone warrior against the Metroids. This initial story influenced the development of subsequent games in terms of gameplay, as well as the expansion of the overall story arc. For example, it determined the types of enemies we would see, and how Samus would interact with the environment. Without this original story, the Metroid franchise would not have the unique identity it has today.
The sense of mystery. In Metroid games, the story often unfolds gradually as you explore. For example, in the original Metroid, you start with little information about Samus' mission and the world she's in. As you progress, you discover more about the Metroids, the Space Pirates, and the secrets of the planet Zebes. The isolation of Samus in these desolate and dangerous environments also adds to the intrigue. There are also plot twists like the revelation about Samus' true identity, which was a huge shock to players at the time.
In Metroid fanfic, a common and great storyline is Samus getting stranded on an unknown planet filled with dangerous and unique creatures. She has to use her skills and the limited resources she has to survive and find a way off the planet. Another good one is when there are alternate timelines. For example, what if Samus didn't destroy the Metroids as she did in the main storyline? This can lead to a whole new set of adventures and challenges for her. Some fanfics also explore Samus's emotional side more, like how she deals with the loneliness of her job, which is quite interesting.
Well, starting with Metroid which introduced us to the world and the main character Samus. Then came Metroid II: Return of Samus which continued the story of Samus' battles against the Metroids. Super Metroid is a classic that further developed the story and gameplay. Metroid Fusion added new elements to the story. Metroid: Zero Mission was also important in the story's progression. The Metroid Prime series, including Prime, Prime 2: Echoes, and Prime 3: Corruption, told the story from a different perspective but still within the overall Metroid universe. Metroid: Other M and Metroid Dread also added their own twists and developments to the ongoing story.
The story of 'Metroid Fusion' is quite good too. The idea of Samus being infected by the X - Parasite and having to fight against it while also dealing with the computer, Adam, that controls her actions. It's a story full of tension, with Samus having to constantly battle not only external enemies but also her own internal struggles as she tries to figure out what's really going on with her body and the station she's on.
To be honest, it's not a very common topic for novels. However, you might find some independently published or fan-written works if you search hard enough. Maybe on specific fan fiction websites or indie publishing platforms.