i have a good answer. you can create a game from scratch with ai, but that will take much longer, cost more, and be buggier, because about half the code is usually the engine itself.

so not only is it a ton of code to write but it's a lot to debug and test. that said, it's a lot of fun writing your own engine from scratch if you are into that kind of fun. but if you want to make a game, why write the engine also?