The things we got to do were a boat trip, parrot park, waterpark, beach,
trip to Mogan by boat they have a yellow submarine there.
The trampolines as you said, a little park with swings

not very good.
Why not hire a car a drive to other parts of the Island, we drove round the whole Island.
We also went horse riding in the mountains, kids there about 7 up, not sure of minimum age.
Go karts and mini bikes is a must.
Go to WHS they have a little travel book (by whs) on Gran Canaria.
We found lots to do in there, and I had been there 3 times before.
Also ask question on google...
Take a look a the DUNES, fun to roll down.
Pedelos, water sports.......
Have fun.
karen
Karen