Congratulations, everyone involved in this project. You have successfully created a character who can bring up all the things I had used to make fun of the very idea of this game, and done so in a way that makes me upset that it's actually happening. That's just good writing.
In the first story of Holiday Star, there is a moment when Miru and Kaku decide that in order to get the Le Bel family's Christmas Tree, they will use a TANK. Immediately followed by Yuuya showing up with an assault rifle.
Shuu gets a moment of Awesomeness by Analysis in the same chapter: He figures out who Miru and Kaku are from the ruins of the student council room, and devises a weapon that will only affect them and won't be fatal by exploiting their allergies.
In the second Holiday Star story, we get to meet an all-new villain, and see his plan. He's planning to blow up your school with a laser powered by otaku and you decide to defeat him...by going even more Crazy Awesome than he is, and become magical girls to raise a barrier to defend the school. It works.
And when it's revealed just how insane the King actually is, Nageki snarks about him being overly wordy. That takes balls on that bird.
I think Yuuya's standing up to the King deserves an extra mention. The whole time, the King has been tempting people by picking at the insecurities and guilt they have, and Yuuya has plenty of guilt for things he's done in the past - which makes his utter refusal to let the King convince him that much more awe-inspiring:
The King: "So come, become one with the King."
Yuuya: "Thanks, but no thanks. ...you're asking me to hand my guilt over to some complete stranger? Please, tell me you're joking."
The King: "....? The King said, do you like pain? The King does not understand."
Yuuya: "Yeah, I didn't think you would. I don't think you ever will. Like you said, I dirtied my hands with a crime, and I can never take it back. A life lost will never return. The past does not change. The least I can do is remember. I will always carry this with me. This pain is mine. And you can't have it."
Yuuya also utters the immortal phrase "Are you going to follow his orders just because he's the king?"
In an extra Holiday Star scene, it's shown that Sakuya successfully negotiated with an assassin and created a plan to keep himself impeccably guarded—all while he was around ten years old.
The assassin in question makes this scene all the more awesome: his butler, Albert. After a failed assassination attempt by his stepmother (who had also hired Albert, voiding the contract), Sakuya beats anyone else who would try to hire Albert to come after him to the punch by contracting him himself. Until Sakuya gives the signal for his life to be ended, his hired blade will kill anyone who comes after him, since, in Albert's words, "Master Sakuya must remain alive if he is to be assassinated."
When you reach Anghel's ending, you get to have a dramatic, RPG-style battle with Doctor Shuu, involving epic final boss music and a giant tree-like Final Boss. When you win, it's also mentioned that Shuu disappears from the school forever, something that is very cathartic seeing as in order to get this end, you have to have already been killed by Shuu on his route. Payback is truly wonderful.
Both games were written and programmed by one person, the enigmatic Hato Moa. She has a friend who designed Shuu's human form, and... that's about it. The credits on the original version of the game are acknowledging the sources of stock photography. This was really a labor of love!
In the Drama CD's, Ryouta, Sakuya and Okosan decide to investigate the seven mysteries of Saint Pigeonation's. One of the mysteries states that students who draw in the library books get cursed. It turns out that when a student once drew in a book, Nageki picked it up and hit him with it since he hates it when people disrespect books. The thought of Nageki doing something like that is actually pretty awesome - especially because he was invisible.