I've tried a few game projects with coding agents - having never worked on a game before in my life - and the main thing I learned is that the hard part is designing it to be fun.

Coming up with a genuinely interesting gameplay loop with increasing difficulty levels and progressively revealed gameplay mechanics is a fascinating and extremely difficult challenge, no matter how much AI you throw at the problem.

I have very similar experience. I vibecoded a foreign language practice app for myself. It works decent from functional perspective and I don’t see too many bugs. But the biggest productivity constraint I see is the time I need to spend using it in order to understand what is working and where the issues are.

LMK if you finish it, sounds like something my daughter would enjoy!