I was able to reproduce the exploit by remapping my joystick shoot button to the keyboard shoot button. It seems like a little bit of a gray area to me so I wanted to see what other people in the community think about using remapping software to take advantage of this exploit.
No extra software besides the game have been used on my run. If you read the manual of the game which is on steam, there's a file you can change the keys for keyboard. I configured it to:
W Jump A Left (default) D Right (Default) J Shoot (Default)
As I could have total control of movement with the left hand I put the controller on top of keyboard and fired with right hand on both controller and keyboard.
I agree with you, no extra software that presses Keyboard and Controller at same time should be allowed.
