This is actually well-written! It seems like a plausible storyline and the characters are mostly in-character (Tara seems a little off, ahem).
I'm not a fan of the art, but all the characters are recognizable as themselves, which is the most important part. They all have various expressions, too, so this is a minor complaint.
Gameplay-wise, it's relatively easy to do things. I am especially grateful for the letters telling me where the various girls are in school (but it might be better to use their faces instead), and the reminders for Shego are helpful. At the beginning, though, I found it difficult to figure out what to do.
My gameplay suggestions:
* Make buildings you can't go to yet silhouettes only which turn into colour detail when you are able to go there. This will make it less frustrating at the beginning, when it's unclear what you can do.
* Make buildings you HAVE to go to (like the beach instead of school for the beach volleyball game) outlined in light.
* More reminders for events, please! I almost missed the mission with Kim because I hadn't yet figured out the time-of-day system and had to scroll backwards. And I never did figure out how to see the cheerleaders new uniforms after Kim told me to come by and see them.
* It would be nice to have a few generic events at school. How about being able to answer questions about history/economics in class in a way that befuddles the teacher? Or a way that makes Junior desperately stop you? You did design Mr. Barkin, so it seems a shame not to include him more.
* More 'things to do' would be nice. At the beginning of the game it felt like go to school, come home, sleep was it. While the storyline was interesting, the 'go home and sleep' part seemed pointless to have. Perhaps you could have stats that you could build by reading books, gloating, checking out EvilBay after the mission, learning hip teen lingo, buying a few small islands, that kind of thing?
* There is one conversation between Kim, Tara and Bonnie that had Kim standing on the left side of the speech bar...which meant a few letters got cut off and I couldn't fully read what they were saying.