Which steps are missing to make simple bone animation? recently I started a little project in 3d.
So I created a simple model to check how it works in game engine but I'm stuck at exporting this model from blender, because my animation / sequence is broken or something like that.
I downloaded one of freeware models (*.blend file with awesome lowpoly character) from web and tried to export it and load to game engine. It worked very well, every sequence was there.

It seems that I do not all steps that must be done before export, so I asking you, please help me to find what exactly I missing.

Here simple steps that I've done:
Created Cube
Extruded it for few sections
Applied scale &amp; rotation &amp; location
Added armature
Switched to edit mode and extruded another bone (so now I have two bones, root and extruded)
Switched to object mode and applied scale &amp; rotation &amp; location
Deselect all
Select extruded cube, then shift + right click on armature ctrl+p > parenting with auto weights
Then I switch to pose mode. 
Press red corcle in timeline section to record all things.
Move extruded bone in pose mode in first frame and then another move on 30th frame.
Checking animation and it works, mech is deforming as bones moves. Everything seems fine.

Export it as fbx and it doesnt move in game engine.

Please help as it stops me in progress.

Sorry fir my English.
Try shift selecting the mesh and armature and then press spacebar and type Export Fbx. Then chose an export spot and chose selected only if there are any other objects in your scene. Then drag this to unity.