I think the page and intro very clear about the sim.
This simulation game is made for when you just want to zone out and watch your orca vivarium. So basically you do nothing. Its pretty obvious.
But whenever a thought pops into your head while you're spacing out, just jot it down using a 'snake note' and send it over to the vivarium.
Notes will be saved as 'short notes' by default, but you can turn them into long-term notes if you want to—the key is to keep an eye on the orcas' emotion stats. Think of this as a Memory Brain Simulator to help you understand how our memory actually works.
I make very clear guide and instruction before you can access/enter the game, on cover and itch.io page. Read.