Platforms can be any image in your game with a collision shape applied to it. You can create either a "One-way" platform, "Moving" platform, or Revolving platform.
This one is pretty simple. Just select the spatial you want to convert into a one-way platform and it will ignore all collision from the bottom and allow objects to pass through but any objects come from the top will stop on this object.
The moving platform just tweens or interpolates the position of a platform from one location to another back and forth. You can also make this platform wait for a collision before it starts to move by checking the "Wait For Passenger" checkbox
The revolving platform animates a platform in a circular motion. This could be achieved with a basic math equation but it is a lot easier to just use a component. The "Center Position" is the point in space that the platform will rotate around. The "Center Offset" is the radius or distance from the "Center Point" of the rotation. The speed the platform will move in a circular motion.