No changing the project name does not “break the site”. Title generally has no impact on eligibility of indexing except in some very specific cases. Any review status set on your page is calculated by a system that looks at various different heuristics related to your account. I see your issue is resolved so I’m going to close this.
The title should only be used to give information about the name of the project.
If you want to give additional info, use the field "Short description or tagline". It appears right under the title in the grid of games.
Search searches the title field literally. So if your game is called "Cool Name (en/ru)" that means that (en/ru) is part of the name of the game. Before, the name relevancy in search was split over "cool" and "name". Now it spreads also over "en" and "ru" and possibly "(/)". This makes your game a little less relevant when people search "cool" or "name" or "cool name".
There is the meta info about languages. One can filter by that. It is not only something displayed in the info box. https://itch.io/games/lang-ru
Oh, and your game seems searchable again.
