DH and I took DSS (7yo) and DS (9mo) to the above on Sunday just gone.
It was quite nice for the babies, they were in a well segregated area which was for the under 4's though it was taken over by us and our babies! There is a Wacky Warehouse type of thing next to it for the bigger kids (which DSS enjoyed immensely), and we didn't have problems with the bigger kids encroaching on the baby area (as I have seen in places such as Mister Twister's).
There is a little cafe serving healthy snacks as well, and by the looks of it very reasonably priced.
It is free for the under 1's and £3.50 for the over 1's. Which is good as places like Mister Twisters and Krazy Korner charge more like £5 - £6 per child.
They are open all day most days, on Sundays it is 2pm - 6pm. There is also Toddler's Time on Tuesday and Friday morning.
It is inside Thornaby Methodist Church, on Stanstead Way very close to the town centre. Coming from the A66/19, go onto the A1130 and turn right towards Thornaby then left at the lights by The Roundel. Stanstead Way is the left hand turn just before the main traffic lights by the schools and just before Thornaby Town Centre - the Church itself is signposted. The Church is at the end of the road, and there is ample parking there as well.