Platform Behavior + Logic = GOOMBA
example .cap: dl.dropbox.com/u/17634050/Goomba_Movement.cap
When using the platform behavior for enemies and such, make sure to ignore input when it's created.
If you want it to turn around at certain points, you'll have to make detectors. If you want it to turn around when it's about to walk off a ledge, you can use collision offset.