>>11966046 (OP)
You gotta stick with it. The first boss is surprisingly difficult, and has a very narrow hitbox window, especially hard without POW. So grab POW, save it until the boss, using your electricity magic to prevent getting hit and losing it.
Stage 2 is a huge difficulty spike and you will absolutely need to learn the double jump timing (similar to Shinobi 3 btw), so spend a while getting that timing down.
After that it's a lot smoother sailing. Just take things slower and more methodical, make smart use of your magic, remember that the end of each stage always refills to one magic, and you can have two magic if you find one in the stage. So make sure to try to find as many items as you can, as there is tons of hidden secrets.
I hated the first hour or two, but then I really warmed up to it and became one of my favorite action games of the era. I love the creative level design and bossfights, and the high level of challenge, methodically breaking down each stage and taking things slow and careful.
Shinobi 3 is a lot different. The challenge is near non-existent, at least early, and it showers you in health. It's more cinematic, and more about just going fast and looking stylish, well at least until level 6 where the difficulty spikes massively. For the falling rock section in level 6, you need to know the double jump timing even more consistent than the first game, despite it barely teaching you or requiring it in previous levels. I think Shinobi 3 shines more on Expert where the halved health makes it so you can't just facetank everything in the game (honestly should have just been the default setting, vast majority of deaths are from insta-kills anyways)