Elmofongo: Also are you justying starting with 30 hp instead of max 99, and not being able to shoot alll directions?
Starting with 30 HP and empty containers is BS; there is no real challenge in filling up your health it's just a tedious waste of time to stand in front of a pipe and keep shooting at bugs. That's on of the thing I'm glad are gone.
However, not being able to shoot in all directions is a more interesting topic. It's basically about balance: in the original Metroid not being able to shoot downwards, diagonally or duck made you think very carefully about your positioning. Bombs were an essential tool for dispatching enemies and with swooping enemies you had to carefully time your jumps and positioning in general. At first you might just run and shoot, but after a while you would start being more resourceful, jumping above enemies, laying bombs in advance and so on.
Having a more flexible moveset like in Super Metroid is not a bad thing in itself, but the game has to be balanced around it. That was not the case though, enemies still had similar movement pattern to the NES, which made Samus overpowered. Case in point, how many times di you use the bombs as an actual weapon in Super Metroid? I never used them, unless I was practically forced to (like being in morph ball mode in a tunnel). How many times did you have to stop and think before you shoot? Not that many times. Of course if the enemies had been properly updated, then a better moveset would have been a welcome addition.
The difference between starting with 30 HP and having a limited moveset is that the former is just tedium for no added challenge while the latter does actually provide more challenge. The difference between the two is easy to spot: ask yourself whether what you are doing is actually making you more or less excited. If it is making you less excited it means you are just going through the motions, doing something that shouldn't be in the game in the first place, like standing in front of the same pipe killing the same bugs over and over again. After a while it gets just boring and the only reason you get hit is because you are getting tired from it.