It's a pleasure to see the world continue to grow with each new chapter! It's very cool to see big dialogue illustrations for all of the characters. I also really like the addition of lewd scenes! The option to skip them for those who enjoy playing the series without overtly sexual encounters is a nice touch.
I like the idea of the investigation puzzle, but I feel like there should be multiple routes to identify what happened. An alternative solution would help those who get stuck by not examining something or talking to someone at the right time. The sliding puzzle was neat!
I feel that RPG Maker is somewhat limiting your potential, though you may be able to go around the issues with addons depending on which edition you are using. The first is the need to look up to interact with objects, I think that in the previous game the wizard had an upwards facing sprite to clarify this, but it's a bit ambiguous here and could be a problem for those unfamiliar with RPG Maker mechanics. If possible, it would be ideal to prevent this behavior altogether. The other is the size of the sprites. This series always featured some lovely pixel art, but it can be hard to see, I would love it if there was an option to play the game in 2x resolution.
Great work, I'm very glad that Rubber Wizard has become a common character in these jams!