I love this game, it's feels really nice to play this formula in a familiar place like Peach's castle. This idea has a lot of potential and it would be really nice to see this done with other areas like the basement and courses and even other classic games.
There is just one major problem I have with the game, and it's that anomalies can appear right in front of you. This makes anomalies that could otherwise be subtle and fun to find way too obvious, which is a shame and definitely something to reconsider for any updates or future instalments. I'd suggest a script that checks the camera the player is looking at and delays anomalies appearing there until they switch to a different one.
Once again, really good game, it's fun and the anomalies are well-made. I hope you keep making games, of any kind obviously!