Don't send hundreds if applications. Find jobs you want and positions where you are a good fit (know relevant Lang platform at least from school or hobby project etc). If a position asks for an experienced person - don't bother applying! Send a small number of very good applications.

A junior position at a mobile games place should definitely be a good fit if you can show a portfolio of such personal projects.

Find people to review your resume and letter. Pay for that service if you can't find friends or people e.g here on HN. Make sure to find people in your own job market to do this - so if you are looking for work in Germany then find Germans to ask for help. What's expected in an application is very regional.

Go to meetups and talk to people.

Finally, when you are rejected after an interview, ask someone for feedback on your application and interview. Ask them to be open about what you could improve. It could be something trivial like spelling.