Platformers
You understand the curtain fire (bullet hell) mechanic really well, I'll give you that, but you're missing a lot that actually drives the platformer genre. This game is very well built, the atmosphere is nice, but the mechanics are way off. Enemy timings and behaviors are awful for both regular enemies and bosses. While it may seem like the enemies have a touch of randomness to them, this is not the case. The problem is that you telegraph what the enemies are going to do very poorly or not at all. This is pivotal to appropriate reaction time on the part of the player, otherwise they spend more time cautiously approaching enemies than actually playing the game - unless, of course, you've memorized every enemy's pattern in the game (This is what game developers do if they test they're own game and what testers do if you don't rotate your testing groups).
The platforming is overplayed. I honestly started to ask myself when I'd reach contiguous ground. I became more irate still when I found that the running trend was going to be a monster that took more than one hit on a platform large enough only for it and nothing else. Magic didn't terribly help this either, since it made sense to shoot the enemy with a fireball and have them walk off of the platform. The problem with that is that you run out of magic quickly and then in turn have no support skills.
My honest recommendation to you is to play the classics again, man. Mario, Sonic, and Mega Man. Since your gameplay style most closely resembles Mega Man Zero, I recommend playing Mega Man Zero 3 on the Gameboy Advance. Focus hard on what really makes these games work and work well.