u need to focus on building a common theme by using symbols, motifs and imagery throughout the piece. basically, you want a piece of writing that reflects the idea of the journey that you are attempting to demonstrate but without being overly blatant about it. considering the time restraint, its quite often the quality of your writing and how skillfully you've encorporated the message of the piece (ie. be subtle about it!) that will get you marks. also a big BIG plus is concept originality. try writing from second person (not as common as youd think perhaps), as an inanimate object, plant etc. anything like this will make your story stand out. HOWEVER, dont fall into the trap of making the creativity of your story more important than the message.