I like the concept of switching between two characters to make use of their strengths.
The keybindings are a bit strange. The entire game can be played with the left hand on WASD, Q and Spacebar and the right hand only really has access to the space bar. Most people are right handed though so if you are going to make a one handed game, perhaps choose a second set of keys for the right hand. That way people can also choose to use both hands as they assign actions per hand.