> I feel like I must find a work not related to computer science
I'm not sure if you've already tried this, but in addition to applying to jobs related to your side project I suggest applying to other jobs that have a lot more jobs available. My guess would be the number of jobs for mobile game dev might be limited and competitive and that would make it difficult when applying as a recent graduate. Web technologies whether for front-end or backend development are greatly in demand and are worth considering.
I'm not sure if you've already tried this, but in addition to applying to jobs related to your side project I suggest applying to other jobs that have a lot more jobs available. My guess would be the number of jobs for mobile game dev might be limited and competitive and that would make it difficult when applying as a recent graduate. Web technologies whether for front-end or backend development are greatly in demand and are worth considering.