I tried to keep this as lag-free as possible, and it seems to be working (as long as you have a decent processor >_<). Arrow keys to move, Z to shoot, X to jump, shift to dash, down to duck, hold C and press the arrow keys to lock in place and aim, and up key to aim up. Cheers.
darkblade12 for original and to sans130907 for a reason why added boss hp
