Hello TheDom, thanks for your post. I downloaded the project you posted and I learned some new features. The bullet behavior has the option to bounce off solids but unfortunately it doesn't work in combination with the platform behavior.
An object with platform behavior has no speed on landed. So I decided to place an invisible object 3 pixels before the solid. When the ball is falling and collide with the invisible object I multiply the VectorY with 0.5 the ball bounce off until it stay still on the solid ground. There is one problem. Sometimes it work, sometimes not. I think because the system detect the collision too late and the ball has no speed at all to multiply when it touch the solid ground.
How can I add just a bounce off behavior to the platform behavior?