I am trying to play the game in Russian, but all the in-game text is mangled (see attached screenshot). This includes text in the settings, dialogs, etc, making the game completely unplayable.

Has anyone faced this problem or knows how I can approach this? Is there anybody who tried to play the game in Russian and it worked fine?

I imagine that I lack some kind of encoding codec or something like that, for Cyrillic text. I guess they did not use a standard utf-8, but something else back in the day.

I've just bought the game and have exactly the same problem. Please let me know if you solve it, thanks.

I've found the solution, but it is system-wide so could affect other applications, not only Evil Islands. Anyway:
(on Windows 10) Press Start, type Region, open Region & language settings - Additional date, time, & regional settings - Region - Administrative - Change system locale - select Russian (Russia).