For browsing the web, the UX site has a great answer.
My question is about games, not forms.
How long from the time a button is pressed, should the player's character react?
On the one hand, instantaneous could be nice. But how would that affect the visuals? I would expect some sort of preparation for the character's actions. For example, jumping would require some bending of the knees first. Swinging a sword would involve raising the sword in hand first. Neglecting these preliminary animations could feel better, but may not look nice. So should that preparation animation not exist? Should it be 100 ms? Can it be up to 500 ms?
On the other hand, many games add intentional delays to require timing by the player. Falcooooo punch! This is not what I am asking for this question, but I figured I should mention it.
So assuming we want instantaneous results for the player, how much time can be designated to the preliminary animations? Does 100 ms (as referred to for the forms answer) also apply to games? Or is there some other strategy used to find a good sweet spot?
And to address the inevitable "You must playtest!" answers - absolutely! But what is a good starting point? As an indie developer, I don't have the ability to iterate much on animations.