Every cat and kitten is different. Most are super playful at that age - most typically start to calm down some when they hit 5-6 months. Getting them fixed early tends to help also. The typical 'calm down' happens around a year or so. I have 1 year old cat who's always been lazy since she took up here last year as a kitten...my other 3 are near 4 years old now and they go through spells where they make like tornados and rip through the house for an hour non stop. Laser lights are a godsend. - lol.
RoPo - when shes in another room, throw a tinkly ball, or while her back is to you, bang a pot or clap your hands...tap the floor...if you get no reaction - shes deaf. usually cats are SUPER curious and want to check out any noise - or jump at sudden noises atleast a bit. The fact her ears don't even swivel around and register to sound is a red flag to me that shes probably totally deaf or severely hearing impaired.
I will tell you 2 great tricks/toys for sight interested hyperactive cats - a nail, a string, and a tinkle ball with ribbons tied to it (or something with alot of flowy moving ribbons/strings to catch their attention) also best if your string is elastic. - nack the nail in the middle of an open doorway, put the ball/toy just above her head height at first, and show it to her. bat it so she gets the idea. hours of entertainment that doesn't get lost under desks, furniture, or appliances ( i have to do weekly runs with a flyswatter or broom under everything to get all the kid and cat toys *sigh* ) as she grows and as she gets the hang of the ball and jumping and backflips, raise it up an inch or two, or drop it back down sometimes for a bit of spice and so she has more work to do to get the ball.
#2 - a short low to the ground fan with a heavy/weighted base, when I go on vacation I ziptie a bit of hardware cloth to the front of a fan (so the cats aren't stupid and stick their paws in it to get caught by the blade *sigh* ) and tie ribbons to the fan - some short and some really long so they just wiggle and don't actually get blown straight out.... has proven to be great entertainment for my cats. I sit a brick on front and back of the base so the cats can't knock it over.