Good eye! Between DD14 and now, player attacks were slowed by 2 frames and the damage modifiers were smoothed out across the board so that the majority of the player's damage dealt would no longer be from the first hit you deal that puts the enemy into stun. The enemy's actual hp values haven't changed, but the player's ability to deal large spikes of damage were modified.
I've been leaning on the fence about lowering the enemy's maximum health but having him get back up with the same or ever-so-slightly-less hp on successive knockdowns. Right now he has 1000 hp for his first life, then when he gets up he gets either 800 or 400?, if memory serves. I've been thinking of reducing his first life to 800, and then making successive knockdowns 600 and 400 instead to make him feel less damage-spongey. As-is it's actually possible to take out his entire third hp bar in one go if you go into his second knockdown with full super and retain it over the duration of his rising attack, but a new player probably won't have a deep enough grasp of the game's underlying mechanics to do that on their first run through.
Also, yeah, the art stuff remains a problem and something I'd like to fix, although it's something I'm not actually capable of fixing right now due to longstanding problems in getting art for the game. There's tons of big and small modifications to the existing sprites I'd like to make but can't, and it frustrates me to no end. You have no idea how much the fact that the player's waistband briefly changes colors when you block messes with my OCD... but I can't fix it because it's partially transparent and any attempts to alter the coloration makes it stand out and look weirder than it already does.