I was honestly expecting a 5 hour game from Metroid 2, so recent news has left me pleasantly surprised. In regards to other Metroid titles:
1). 2D Metroids-
I've loved all Prime titles which got my interest in the 2D titles. Fusion was my favorite. Both SA-X and when you ventured off the beaten path were the most memorable parts of the game. I enjoyed it the most as I felt it had better controls and QoL improvements to Fusion over Super Metroid. It also was more engaging experience than SM and a lot longer than ZM. Zero Mission felt like a taste of Super Metroid with improved design choices, controls and QoL improvements. It was fun for what it was but it's harder to compare a 3 hour adventure to the other lengthier titles. Much like my experience with ALttP, I see why it's held to such a high regard. However, there are some design choices in both SM and ALttP that feel a bit archaic and frustrating which is why I don't personally hold them as highly as others. Don't get me wrong I enjoyed the titles just not as much as others.
Metroid: Other M- Controversial opinion but it had a lot of good and different ideas to the series. However, it was marred with terrible design choices where it seems like Sakurai and Team Ninja had different visions for this title. Which resulted in a hog-pog of different gameplay styles and bizarre design choices. I feel it could've been a salvageable project but it was a mess from story to gameplay. It should've been designed eith the nunchuk. They should've allowed for movement while in first person mode and made more interesting gameplay design built around switching between the two perspectives. The story and characterization would've gone a lot better as a prequel to the original Metroid. They could've given us short haired Samus while defiant and a loner still takes orders from Adam. The PTSD thing of seeing Ridley would actually make sense. After Ridley's defeat, Samus gains the confidence to do her own thing without following orders to defeat Queen Metroid. After Adam's death, uncovering GF's dark side and growing independent she quits the GF and does her own thing. It still wouldn't have fixed the long cutscenes of Samus going into lengthy monologues about her feelings. However, since it would be a prequel to Metroid it would at least cut out "the Baby" talk which was at least 35% of the monologues.