This game has such a unique gameplay, but it is easy to understand and fun to play at the same time. It took me one or two rounds to completely understand it and after that, shutting windows and doors quickly became addictive. The whole game feels super polished. The light (love the color and the god rays), the ambient background and the empty rooms all come together to create a very strange vibe which is great.
By replacing the "Karen" model in the latest update, you took away the last point I found to criticize :D The new tentacle remnant fits way better and the particles + sound effect feel very satisfying when you remove a remnant. However, I didn’t quite understand what the circular animation at the cursor represents when a remnant is removed. What does it indicate?
The room generation feels very varied and surprisingly natural. Sometimes I encountered very long rooms with just one window, where the god rays would not touch every corner of the room. Can remnants hide in areas not touched by sunlight? In my case, if there was a remnant in the room, it was always close to the window and I got it.
The game already feels complete in its current form, and I don’t think it needs any expansion. It stands well on its own. However If you plan to extend the gameplay, I could image a game mode where you clear multiple consecutive levels (like floors in a skyscraper). When you shut everything you can enter an elevator and go up to the next floor. Each floor could get bigger and introduce new gameplay elements over time.