This is the movie to reproduce the following glitch in Battletoads shown here: https://www.youtube.com/watch?v=i0h4quApjOE&ab_channel=LobsterZelda
I have no idea what causes this. It seems that player 1's health actually goes up by 4 each time they're hit here, and then drops back down to its original value in a few frames. This continues until you move away from the enemy. Also works on the right side of the screen.
This was done on the PAL version of the game.