I've been quite often over the past two years; first when O was small it was a good rainy day option, then when preggers with J - it was a good option as it was a contained space and I did not have to run too far to keep track of O and now with a three month old - it remains a super space for this same reason (safely trapped!).
Kidspace has little wooden teepee like tents with different things to explore inside - dinosaurs, spiders and the like... a box of tails to put on... reading corners... magnifying glasses with insects set in resin to examine (as pictured)... taxidermy animals... and loads more. The space is for under 5's and I think they have scheduled activities some mornings of the week. Kidspace also has change tables and a soft play area for crawlers too.
Entry - we also bought a family membership. Worked out that I had to take the kids by myself 7 times (a year) to make it worthwhile/cheaper than single entry. Most times I go with Mum and Hubby so then it's even less visits to make the membership option the better choice.
Parking tip - I drive and park at Interpark Domain Car Park it's a flat rate of $10 on the weekend. This site is also a good site to search cheap parking. Check rates before you go though.