I noticed a star on the roof of my Research hut. Is this new or was it there the whole time I did not notice it before?

Thanks a Bunch!

You have collected all the Shells

There was a topic about this i was trying to find the link so that you could go see without anything being spoiled, expecially since you dont have spoiler in the topic so will just do it this way, highlight the space b4 the "start" and "finish" to see the answer for your question.

SPOILER

Start

The star on the hut is the games way of saying way to go you have finished one of the collectables, you will be getting a butterfly and a pebble and beetle right beside them as you finish those things.

Finish

You should also have received a pop-up message when you got the last shell.