I recently created a tiny space ship, it looks like this in Blender:

but when I import it into Unity it looks weird and the animation is broken(no bones only scene graph):

Check if scale is applied - in object mode Object>apply>Rotation&Scale. Make sure you select each separate mesh. Check if any modifiers are applied - In properties Modifiers...apply any that are there. Then check the bones are parented correctly. Export as a fbx. Select the space ship mesh and bones in the rig. Then check in export box the Selected Objects and check experimental apply transform. Drag and drop the fbx in to unity assets or any file.