Fighting piracy by making the game worse for actual fans (by moving crucial game logic server-side) is a very bad solution imo. I believe in the way of GoG.com
Because if people really like your content, they'll pay for it.
So I think the best solution for all is make it easier to get the game the legit way, and not the illegal way, by:
1. Make sure you're visible on the web. Search engines, SoMe, etc.
2. Make people emtionally invest in you and your work (by being sincere, and not by trickery).
3. Asking hosters of your pirated content to take it down, or if they refuse, make them include a link to where to by the content, if they like it (i've seen work before).
As of how I found your game, I saw it on youtube (the video below) and I wanted to search for your itch page, but the first result (on duckgogo) was a clearly illegal site: https://extrogames.com/game/star-explorers