Zerosquare (./51) :
I think it would look even better if areas that have been hit progressively faded from red to "normal", instead of just having two states (red / "normal"). Maybe this is doable with palette animation?
There's also a tiny bug at 1:02 : the left arm stays red for too long. It looks like the countdown timer stops when an animation is in progress

Thank you for your advice - I have found the hit palette bug and fixed it (the reason was a incorrect if-else construction).
Yes, fading in/out of the hit palette would look great but it would collide with the "attacking side" palette (from black to yellow).
Originally, I had added a fade in/out of the "attacking side" palette but scrapped it to keep the code simple and fast.