The idea was good, but the controls were not well optimized
for the concept in my opinion. You have to constantly
switch between positioning your hand on different areas of
the keyboard and the mouse, especially because you can not
switch characters while still having you hand at the
movement keys position. Could be solved in numerous ways
including enabling WASD controls or alternatively letting
the player switch characters by (right/left) clicking their
window. That way you have one hand at a certain area of
the keyboard and the other on the mouse and have more fluid
control.
Also it is important to note that it is not very clear that
you need to press ENTER to start the game and that is
probably why ice cold muffin posted that he is confused.
Overall I think that the concept has a lot of potential and
I liked the colors that you picked, keep it up