Cut a picture (png) in Unity

Hello, I have got a ‘noob’ question.
Now I am having a problem : I did a platform in Photoshop, and I want to put it into Unity. The picture is as png, so it’s already cut. When I drag my png into Unity, the transparency is respected, good.
I add a new component to my png, box collider 2D I think. Now my png is a pratform. But when I start the game, my character fly until the top of the picture to idle. Because the picture has just the transparence, the outlines are not respected (sorry but my English isn’t very well, I’m french).
I send a capture to understand my problem.

It would nice to fix it quickly. Thank you Unity’s community !

you have three or four choices:

  • split your images up in Photoshop.
  • split them up in unity.
  • add multiple colliders to the gameobject and adjust their position and sizes.
  • add multiple gameobjects with colliders as children and adjust them