I think it depends on how you use the keyboard. (I don’t really play video games, so I could be off base here.)
It seems to me that there are two types of video game keyboard mappings here. One type focuses on a few commonly used keys (like the arrow cluster) and your wrist stays in a relatively static position, reaching for keys in close proximity to that standard home position, and mostly using only one finger for any particular key. Another type of game uses very many keys, and top-level players and up moving their left hand back and forth over larger areas on the keyboard and potentially even using different fingers to type some keys depending on what else they’re typing. In this case the keyboard is being played more like a piano or something.
There’s also a difference between patterns where several different keys must be pressed in rapid succession vs. patterns where the same key needs to be pressed repeatedly. In the former case, most of the motion is in the fingers themselves, whereas in the latter case it seems to me that much of the motion comes from whole-hand movement. These two patterns might benefit from different types of keyswitches or arrangements of keys.
For the type of game where you have a few keys getting most of the attention, and use one finger for each key, I think something like this in a relatively flat shape could be pretty effective (probably with a different character mapping):
For the type of game where you need many keys with some fancy fingering strategies, it would probably be more effective to have some kind of matrix layout or something, with some gaps between blocks of keys so they’re easy to find. It might also be helpful to have keys at different heights, like the black keys on a piano.
Regardless of what layout you pick, you want to think carefully about which actions you need to invoke in what order, so that you can make a fingering which optimizes comfort and efficiency. For example, the middle finger, ring finger, and pinky finger use some of the same muscles for their movement, so it’s very difficult to alternate back and forth between one and another of them in quick succession (though you can pretty quickly do a “roll” from one to the next as long as the first finger doesn’t need to be immediately pressed again right after). So if you need to alternate two keys quickly, you should use either the index finger or thumb for one of the two keys. If you need to alternately press three keys quickly, you should try to use index finger, thumb, and a third finger (which third finger depends on how far spread the keys are).
