My hunch is he's not using Claude Opus 5.5.
Making a fun, polished game, and not just a quick prototype to post screenshots of on social media, is not just about choosing the right LLM model and telling it ‘make a fun game’
I was as surprised as you are.
Making a fun, polished game, and not just a quick prototype to post screenshots of on social media, is not just about choosing the right LLM model and telling it ‘make a fun game’