Hi LeHuuLoc
Obviously you are talking about shadows, not shaders

Better ask in the scripting-forum. To achieve this, you would need animated shadow sprites of your player movements (named something like: player_shadow+10.pcx). Their frame states will need to be synchronized with the player movement frames (wich is hard to achieve and only works well on flat ground). Maybe it can also be done with a rather complicated projection-shader.
If you are new to A6, better try to accomplish more simple task...what you 're asking is already medium to high level...I guess
