Thank you, GenericPerson! The timer is on my to do list. It seems when competitive people are against each other, they tend to have more calculated moves instead of slugging it out, and 20 seconds just isn't enough. I'll add settings for that. The boxer's health adjustment is also a good idea, I can add that too, thanks for the suggestion!
For the block, I'm thinking of adding a guard break, maybe after 3-4 punches, with or without an additional display meter, just to prevent abusing block.
I have to admit though, the AI turtling after dishing damage is kind of funny!