Had my son's 5th birthday here yesterday. Absolutely brilliant. Great instructors who took the 30 odd kids and kept them happy for over an hour. Had a separate room for adults/food. Very reasonably priced. Only complaint is that they did not have milk so could not make coffees for the parents, and did not let us bring our own. We were allowed to self cater food, though.
I have been going to the Walkerville YMCA (aka INEA YMCA) since I was a little girl. And in the last couple of years they have made some massive changes to the facilities and programs offered, making the centre even better. They offer a great after school care and vacation care program for primary school kids, several different programs for gymnastics, trampolining, fitness classes etc. They also offer basketball and squash courts, run kids parties (which they love) and more. They have recently started running a program called Stunt Monkeys which I cannot wait for my daughter to be old enough to try. There is something for everyone and I know the staff keep me motivated to get down there for a workout regularly.
My son has done gymnastics there for about 2 years and now has moved on to trampolining. The instructors are good - Jen is FANTASTIC - she's a trampolining professional herself so she provides excellent coaching. Other facilities include squash, cardio, physio, kids parties and more. Definitely worth a visit for kids gymnastics.
Approximate cost: $150 term