I'm really impressed with this game, its got a ton of charm! It's unfinished currently, but it seems like the core of the game is done and you'll be able to add the rest. The fourth wall breaking message for the end seems to fit the story. You have multiple working mini games, and you captured the vibe of Windows XP immaculately. I really appreciate the little details like the time matching your computer. You've got a ton of different expressive sprites for Mizuko, and the writing is really great. I hope you finish this so I can read the rest!
Two pieces of feedback: This game definitely needs the sound bug fixed. A good soundtrack and some sound effects will really help sell the experience, especially when it gets glitchy. When there are new messages received as well I would consider scrolling to the bottom of the text screen automatically as well rather than the player having to scroll for every message.
Excellent showing, I hope you continue to work on this!