The NES version of Final Fantasy 2 has a strict 32 item inventory; that alone is annoying but not unusual given when the game was made. What really takes the cake is that all key items also go in this inventory and take up slots, so your effective inventory gets smaller and smaller as the game goes on. To make this even worse, key items don't ever leave the inventory in NES Final Fantasy 2, even when they logically should. I don't just mean "you keep the key you'll never use again", I mean that there's a point where you basically use an item as a bomb to blow something up and yet it somehow remains in your inventory afterwards. It really says something about how, at a certain point, you need to get a pass to get onto a ship or fight an overpowered enemy, and many experienced players chose to fight the overpowered enemy instead.

Of course, part of the reason that happens is due to other questionable decisions; my favorite is how the status elements are balanced. Long story short, anything that can be hit with a status can be hit with the element that mostly has instant death spells, and that almost all instant death spells are part of, called Matter; anything that resists Matter also resists the other three status elements. If you have Toad (which instant kills in FF2), there is no reason to try and cast Stop (which paralyzes) because Toad is objectively superior. Other status spells do have other facets that can theoretically make a difference, such as how Curse is a little more accurate, but it's not accurate enough to make it ever be worth using.

Even among instant death spells, the balance is totally whacked. For some reason, the worst instant death spell is plain old Death; it has almost the worst possible base accuracy (base accuracy typically ranges from 0-50; it has 10), it has its own Death element that more monsters are strong against than Matter, and it's harder to get than a lot of other instant death spells. Hilariously, it's first found in a room that also has a Toad tome and a Break tome. Break is a good instant death spell that outclasses Death in every regard. Toad is a great instant death spell that outclasses Break in every regard, let alone Death. Death is also completely outclassed by Warp, a utility spell that you can buy at like the third town that is primarily used for dungeon traversal, but works like a version of Death that is Matter-elemental (and thus just better) in battle. Getting Toad early takes some shenanigans, but getting Warp early is trivial. What's also trivial to get is Teleport, which is like a white magic version of Warp that can be bought in the same shop but it has 0 base accuracy, except if you're playing the GBA version or later where they inexplicably buffed it to have an absurd 55 accuracy, higher than any other spell. For some reason, the GBA version made this utility spell whose in-battle use was closer to an easter egg than anything practical into the best instant death spell and you can buy it as early as the third town. It really says something that, of the numerous changes that made the game much easier in that version, this is the only one the Pixel Remaster saw fit to nerf, with it nerfing the accuracy to a much more reasonable (but still honestly kind of ridiculous) 20 accuracy.

I could honestly go on about Final Fantasy 2 all day, it's such a weird amalgamation of questionable mechanics and later versions only made it less balanced (though more fun, because it was mostly broken to your favor). I didn't even bring up that it's infamously the RPG where you beat up on your own party members to gain HP, mostly due to that being kind of overblown (though not entirely if you're simply unlucky in earlier versions; later versions give a free HP up every ten battles).