Hi Fatih, this looks really cool! I just had a play of the demo - are you using original music or have you got stock music? I'm a composer and this sort of game is right up my street. I'd be happy to compose 10 minutes of music for free, just for fun and for the experience. You can check out my past work on my website: https://www.hughholbech.com/
I did the music for a similar kind of game, 'Never Second In Rome:'
Best of luck with your game!