ok, so to start it off...
the red bar represents ur health. it will go down as u take damage and when it reaches 0 ur dead...
the blue bar represents ki. ki is needed for doing attacks; beams and melee, turbos; default 't' which increases ur powerlevel, or flying (swooping).
ther r two kinds of melee:
1. basic melee
to do this u will need to be swooping (double tap 'w') and make contact with an enemy (if you hold right click, which would make it into a hit). it consists of 12 pre-punch hits. during this period u can right click to swicth it to a swing or continue to advanced melee. if ur ki runs out during pre-punch melee u will be knocked back.
2. advanced melee
during the 12 pre-punch melee click any direction while holding the left mouse button. the strength of the punch can be seen in the bar starting with green to blue to red. the stronger the punch the more damge u will do to th enemy.