The game explored a lot of really cool concepts but probably not the best introduction to Metroidvanias for me. The art was well done and the environments all were very well put together and immersive, Music was alright but sometimes got annoying to me.
I really like the concept of exploring to unlock new abilities and upgrades, and I feel like all the upgrades in Metroid III are good and I was always excited to find them. They always made a good payoff for completing whatever challenge was involved in finding them and I liked the "aha" moments I would get upon realizing how new things I found would help me in areas I'd gotten stuck earlier.
That being said, a lot of required content was just straight up hidden from me. Not just guarded by a platforming or combat challenge, but literally just hidden away somewhere. Now don't get me wrong, I think hiding optional content or upgrades (such as energy tanks or missile capacity) in hidden areas is a cool concept that rewards an explorative player, but there were several times while playing where I felt like I was unable to progress simply because I hadn't placed a bomb next to the correct wall yet. I think the items directly required for progression ought to be at least hinted at on the map or by the level design.
Furthermore, during these times when I felt the game devolved into a "room checking simulator" it was not helped at all by the fact that there were multiple ways to check a room, each of which took time and required me to switch what ability I had selected (more on those later.) Also, there are just a lot of rooms in the game. Not to mention that the "best" way to check a room, was with mega bombs, which are an expendable resource that you need to stop and collect more of if you run out before you find anything.
At this point, I can't talk about anything else in this game without addressing the elephant in the room: the controls.
The controls hurt this game a lot not only were some of the ability controls difficult to work with, but even the most basic movement just didn't feel good, which is really important for a game involving platforming. At first I thought I'd get used to it, and I did to some extent, but nonetheless those controls were frustrating for the entire game.
I know some of this falls on me for being bad, but there shouldn't be a skill requirement simply to move the character where you want them to. In other games I'm bad at, moving the character exactly how I want to is trivial, and the balance is I get hit anyway for not thinking quickly enough or making small mistakes.
Speaking of, a huge roadblock to me when trying to learn the controls was the lack of feedback when I messed up an input. I won't talk too much about wall jumping because it's an optional mechanic, but this was also an especially glaring issue with the Space Jump ability, which requires you to tap jump to a rhythm, but gives no feedback on if you're early or late with your inputs and the audio queues also could stand to be better. I feel like space jump in particular could have felt awesome to use if better implemented, but as it was I just found it frustrating to interact with.
I think the bosses looked cool and were well designed, they had readable tells and learning how to avoid their attacks would have been really fun if I had better control of Samus. As it was, trying to avoid projectiles was a nightmare, my hitbox felt awkwardly big and I couldn't get Samus to move precisely enough to avoid anything a lot of the time.
In fact, all the combat in the game suffered from how annoying it was to simply control Samus. Many of the enemies felt like they specifically targeted the weaknesses of the control scheme and were just endlessly frustrating rather than fun and challenging.
I don't shy away from difficulty in a game, but I also like to be able to throw myself repeatedly at a challenge I get stuck on. I understand putting a walk back to the boss after you die, but several of the bosses in Super Metroid have these 10+ second cutscenes that you have to watch every time you challenge them. I don't think that a cool boss cutscene is a bad idea, but I think other games handle this a lot better by only showing the cutscene the 1st time, and having an abridged version, or no cutscene at all for subsequent attempts. These cutscenes, compiled with the fact that often times I would die because Samus went somewhere other than where I was trying to move her to just created a really frustrating experience with almost every boss.
I think all the abilities were neat, but switching between them constantly was a real pain, especially during things like bosses where being able to switch to an item quickly could be the difference between damaging the boss and getting damaged yourself. Maybe other metroidvanias all share this same pitfall, but having to constantly scroll through a menu to pick what thing I wanted to use was frustrating and I feel like there had to be a better way, albeit maybe that way is have a controller with more buttons, which wasn't really an option I'd imagine.
Additionally, there were some particularly glaring issues that I found couldn't really be excused, namely:
Overall, I think the game had a lot of good ideas and pioneered a genera of games that I may very well enjoy, but the controls really just made it an unfortunate experience. I do think that later on I was having more fun fighting the bosses, but some of the attacks just felt unavoidable, which frustrated me. If the controls were better, maybe even the room checking wouldn't be that bad, but as it is...