Well, I'm trying to make a platform shooting game on the basis of Super Mario Brothers. There are two issues though...I set the platforms as backdrop obstacles and whenever I jump and hit them, I stick to them. Another problem is that I when I run to my right, the animation for it runs smoothly, but if I run to my left, the animation glitches and Mario teleports a couple feet before actually running. Any ideas on how to fix them?

For the teleport problem that you're seeing, check your player object's Hot Spot - this is the point that the animation is drawn from and acts as the actual position of the object on the screen. To view it, edit your player and click the eye icon on the left of the animation editor - you'll then be able to move it around. There's a separate one for each frame, and it sounds like you might have reversed the animation to make your walking-left frames and changed the position of the hot spot along with them.

Sticking to the top of platforms might be because of the animation of the object changing when it's falling and teleporting up a little into the platform - this could be another hot spot issue.

I didn't comprehend a thing you just said about the platform problem :P Idk, I have my platforms set as backgrops and objects. Should I set them to something else?

EDIT: Also, I can't jump while I'm standing still :S

You can set your platforms to be platform objects and be fine. DavidN was saying that you need to check your animations for your characters to make sure that they don't accidentally fall into the platform. Say your character is 32 pixels tall, but in one animation you accidentally make it 33. Because it changed to this frame, your character is now "in" the platform instead of "on" it, and it screws up the object relationship.

Hope this helps