Okay then... this is my personal opinion...
When playing, sometimes we just use one hand, so to move our character (left, right and jump) we automatically use "Up Arrows/W" to jump, not "Space"...
So i think it would be nice if "Up Arrows/W" has function as jump, not action key
the action key will be nice if "Space/Enter"
so if we play with left hand we will use "A" and "D" for left and right, "W" for jump, and "Space" for action
if we play with right hand we will use "Left Arrow" and "Right Arrow" for left and right, "Up Arrow" for jump, and "Enter" for action :-?
And some dialog boxes can't be close with only keyboard, we must change to mouse to click a button to close it... which is annoying for me :-?