When making a game the "low level details and tiny optimizations" that you want to concentrate on are the ones that make the game more fun: fun little touches.

When making a game the "low level details and tiny optimizations" that you want to concentrate on are the ones that make the game more fun: fun little touches. Sometimes that requires code optimisations but mostly it involves the kind of special-case actions and quirky animations that make for great gameplay but nasty-looing code :)