Yes, from what I have played so far, I would prefer to control the characters individually. That could change depending on what ideas you have to do with the commands later, though.
The idea to use a key combination itself works well, but I intuitively try to use the directional key that would move the kid closer or away from the adult at that given moment rather than memorizing that left or right do fixed things.
What I mean is that the password I get by beating stage x and moving onto x+1 puts me at the start of stage x rather than x+1.