Of casual chatting in between making dinner, doing chores, playing with kids, and work. The actual time spent strictly on this was more like 2 hours. And that's with me writing zero lines of code, and using the technology stack (modern web) I hate and suck at (but I'm proficient enough to read the basics).
Also, to be honest, it would've been much faster if GPT-4o didn't occasionally get confused by the braces, forcing me to figure out ways to coerce it into adding code in the right place. This is to say, there's still plenty of low-hanging fruits for improvement here.
The vast majority of devs would take much longer than 6 hours if this task were assigned to them. Yes, the vast majority of devs might suck, but its actually a shockingly low percentage who are genuinely skilled. You are probably surrounded by rare skilled devs.
Honestly I'm totally in the AI camp but 6 hours to make a 2048 clone?! And that's a good result? Come on.