Myth War II

So, forgive me about not-knowing what to do.

The game is called:
MythwarII
https://mw2.tdt.net

It's a Windows game and run without issues here. In fact, less issues than on Win11.
It's only one think bother me - its great CPU load % during even game log-in window. It's about 50-60% CPU usage, no mater what.

In Windows 11 i got like 2-3% CPU usage.

So i'm curious what making this little game to draw so much CPU?

I do not even know what graphics API are using this game. I guess no one even try this game on Linux. It's a almost forgotten game from original dev IGG.

Maybe someone can look deeper into - what makes this game to load CPU so much?

To reproduce:
You just need download the client(no reg req) and go to log-in window and no need put anything. That is enough to reproduce CPU load.

There is no mater what Proton i use. I use steam's Proton, Lutris Proton .. no mater.

The issue names no Proton source file, test, or entry point. Start by downloading MythwarII from the linked site and reproducing the CPU load at its login window under Proton, then compare it with Windows 11 and the listed Proton variants. Done would require identifying what causes the high CPU usage and documenting or fixing it.