Good beginning
Here's my advice for platform games (I've made 5 of them)
1- Put a reset button or an item with HitTest to reset the level if you lose your ball.
2- Put your FPS to at least 35 fps for smoother action
3- You don't have to start a level where you finished the previous one. Just insert a blank keyframe between each level, will be more easy to control the game.
Overall, it was great, i'm just waiting to see more of you and maybe an improved version of this one ! Keep it up !