Sorry for the late reply.
What properties do you want to change? You can use the State Machine to change properties with Tweens etc. Or use the scripting API.
To make collectable items maybe you can do something like in TRIF, using the State Machine: https://www.youtube.com/watch?v=UCnJDrkkk-8
I don't think we have any good example of a health system in Goo Create at the moment, but I guess it requires some scripting.
Can you provide a link to your scene?