Remember that this is a character development assignment. While I love the action genre, it often has flat characters. So do be sure to flesh out or round out those characters.
You need a header and a title.
Too much showing/summary and not enough telling. (He was shy vs. He found it impossible to look his teacher in the eye or raise his voice above a meek whisper.)
Proofread. Capitalization and spelling matter.
Be plausible and artful: fine tune that cheese detector. (Avoid hyperbole, sentimentality and cliches unless you're using them intentionally.)