If you're having trouble, try simplifying the tree's shape to its basic components. The pine tree you drew is, in its essence, a cone.

So, start by drawing a cone and try to make it at the right angle for your top-down game. When you have the perfect shape, start adding details on top of it, using it as the basis for your tree.

It's a good method to draw complex objects: you start with the basic form of the object, without thinking about details, shadows and so on. Once the form is solid, you can add the rest.

Hopefully, this can help a little. At the moment I'm a bit in a hurry and I can't make a paint-over.