dtgreene: Like in Terranigma?
(Some misconceptions about that game's system cleared up: Some boss fights, including one particularly infamous one, *do* allow the use or magic, and casting a spell will give you the gems used to purchase it back, so there's no non-renewable consumable resource you need for magic.)
Then again, this reminds me of how some Ys games don't allow you to access the menu during battle, which really does feel arbitrary (though at least it's all bosses there rather than just some, so at least that's consistent).
I did look into that game some time ago, and even watched some speedruns, and it does look interesting and atypcial of an arcade game.
By the way, did you get the item that lets you breathe underwater, or did you prefer to skip it?
Dogmaus: the siren's scale? I don't think it can be skipped at all as far as I remember. If you'd like to play it co-op pm me! :)
I don't know terranigma. In Gate of Doom you have a meter that fills up killing enemies to launch a spell that is active at a given time - they cycle. Including a mystery random spell. When you face most bosses the spell meter and book just disappear. In the sequel you are allowed to cast spells at bosses but as your magic meter doesn't refill hiitting bosses it's not so useful. You can only cast one if you saved it for the boss. When you start a new life your magic meter is empty.
Also, the magic meter goes down for the time you are actually using the spell. If you die before it's effect is over, you keep the remaining in your next life unless it's from a new coin.
You can skip the scale, provided you have some way of surviving the damage you take. You might then need to farm XP in the following area to get strong enough to finish the game in a timely manner, however.
Look up Cadash speedruns on YouTube; they tend to skip the scale.
Terranigma is a Super NES game, in the same series as SoulBlazer and Illusion of Gaia, that for whatever reason was released in Japan and Europe but not the US; I've only played it because of emulation, and I didn't get that far in the game. A couple issues I had were the lengthy cutscenes and the precense of permanent missables (like some of the gems used to purchase spells). Also, while I didn't get that far, it looks like your stats shoot up so much at high levels that you can outlevel the game's hardest challenges and make the final boss a joke. (SoulBlazer has much lower stat growth, and Illusion of Gaia doesn't have level ups at all.)
I think ActRaiser is my favorite game made by that company, as I seem to prefer sidescrollers over Zelda-likes (note that Zelda 2 is not a Zelda-like for this purpose), and the simulation sequences make the game unique (and were sadly omitted in the sequl.)
Dogmaus: When you start a new life your magic meter is empty.
Very unlike Zelda 2, where your magic meter is full with each new life, making intentional deaths sometimes necessary. (There's one part, where if this didn't happen, you could get softlocked and have to game over, no matter how many lives you have left. Then again, in the same dungeon there's actually a true softlock.)