Okay, let's go through these challenges one by one...
1 - Not really interesting, but otherwise okay.
2 - Actually gets much more difficult if you move horizontally because of the boss's movement. It also makes the second, third and fourth waves overlap to make one really nasty wave, but is easy before and after that.
3 - If you are not using a character with a small hitbox like Reimu, this attack is pretty much a wall in the face.
4 - Tap... Tap... Tap... Tap... Done.
5 - Due to the random nature, it is possible for the knives to completely block the path through the red balls. Also, the motion doesn't form a real pentagram.
6 - On the first time seeing this, you will die. You will wonder why you died. Then you will die again, and maybe you'll notice that you get bullets of such a high speed in the face that with human reaction time the only way not to get hit is to tap once you see the delay glow. An attack like that without a sound effect that would tell you to move away is just mean, even if it gets easy on the third try or so. Also, the win condition of grazing a certain amount of bullets seems to break now and then. I don't know what causes it, though. Additionally, I cannot run the script if I try to access it outside of the plural script.
7 - That one is fine.
8 - "DODGE AND WATCH THE METER!" "You need this much: " "This much to go: " I', sorry, but, what?! I have no idea what I am supposed to do here, so I just keep shooting and try to survive. First and second form are okay, if still incredibly hard. Third form will, again, kill anybody who sees it for the first time with instant grey arrows to the face. And then, of yourse I am forced to bomb/die because I didn't fulfill the requirements that I don't know.
9 - Would be okay, but I have to mention that if you wanted the blue bullets to be reflected from the bottom realistically, they aren't.
10 - Well, well. The huge clouds of delay mist make both the player character and her hitbox invisible. You cannot dodge stars if you cannot see where you are. Also, it can happen that a ring is placed after one or more stars are already put on a trajectory towards the ring, meaning that you can see neither the charcter nor her hitbox nor the bullets you are supposed to dodge. Also, due to the random placement of the rings, two things can happen. Either the ring is spawned almost on top of the boss, making it almost impossible to dodge the stars, or two consecutive rings are spawned so far away from each other that it is impossible to stay in the one ring until the knives move outwards and then reach the other ring before that one explodes. The card would be nice if it was playing fair, but most of the time it isn't.
11 - Difficult, but it looks nice, so this one is good. Only problem is that the boss's hitbox has a diameter larger than the width of the boss sprite.
12 - That one is okay, too.
13 - When switching from the first to the second form or from the second to the third, the old bullets overlap with the new ones and become garbage. The final form is imposssible when you stay in the middle and extremely easy if you move to the corner. Otherwise, number 13 is very difficult but has nice patterns.
14 - This is a good one. A little more colour could make it look prettier, though.
15 - "Carfeully of the red Bullets. They may aim up, but what comes up Must come down!" Actually, they don't. Also, the language is... improvable. Aside from that, it is like one of Nue's non-cards, but less interesting because the bullets are slower and fly at the exact same angle.
16 - The pattern is okay, if difficult. My main complain here would be that the "meteors" look...
17 - Probably your best one. The colour of the bullets seems odd, but otherwise it is a nice and simple, if difficult, attack.
18 - If you find one spot to stay in, you can stay in that spot until the timer runs out. Finding such a spot, however, is a paint for non-Reimus.
19 - Purple glowing stuff layered on purple glowing stuff.
All in all, most of your attacks die with just one bomb, but even then no attack should be so difficult or unfun that the player is practically supposed to bomb it to oblivion. Except when the script is meant solely for Naut, in which case you can make it as difficult as you want and he still will make it. :V
So, yeah. The general complaints of a lack of sound and more difficulty settings remains. Also, the boss sprite looks oddly stretched.
I hope this wall of text will help you.
