First, I love the depth in this response. You pointed out things that could be improved or are missing and offered ideas to fix them.
As far as the sounds go, I do plan on implementing all of the recommended sounds. I agree that there should be some sort of indication when being hit like a temporary time slow.
I also would like to point out that the attacks Oz is making are claw attacks. The animation is quite fast so I can understand that not being noticed. I will try to correct the animation to make that clearer to the player.
This is why I released the demo to see how people perceived the overall concept. I will work hard to make these changes great!
Great! Consider using the claws to put Oz's life into context. Some more detail around the claws could explain class, income, social status, family history, etc.
Mom knows about the claws, so is it a trait unique to her family? Or does only Oz have claws and that's why he's tasked with maintaining the lawn? Does his brother get unique chores related to another power? Is there a reason Mom can't do yard work? Just small observations by characters can help the player catch up on your OC's lore.