First off, bonus points for getting your kiddo involved in the jam.
You said in your description, 'You have to start somewhere." Your submission was a really solid start. The graphics worked, the zombie looked like a zombie and the brains looked like brains. I liked how the zombie looked like a kid trying to catch snowflakes on their tongue. My favorite part was how the notes when you caught the brains changed and worked with the music.
The first time I played, there was no sound, but the controls worked perfectly. The second time I played, I had sound, but the game glitched on me. I don't know if it was my browser or something else. I'm glad I went back to play the second time, because I the note changing for the brains along with the music was a treat.
Nice job, especially for your first game jam. I hope you participate next year. It's fun to watch people's skills increase year over year.