Salaam brother Nidal and may Allaah bless your effort.
This is a great and effective way you're promoting this issue especially among young people and representing Muslims and our causes in a positive way. I'm personally extremely picky in games and play only War Thunder semi-regularly and a tiny handful of others like DCS occasionally. I dislike the fps category entirely but would make an exception in your case inshaaAllaah :) Hope you can allow player controlled vehicles in the game and make it cross-platform with native Linux support.
I hope you can finish this project and maintain it in a sustainable way. Please don't use music in your game and instead use sound effects, nasheeds, etc to keep it halaal. Also, maybe doing a crowdfunding campaign on launchgood.com (Muslim owned) is a good idea.