Your choice of color is great. It's a respectable cause and doing it in neon green and red and yellow would've been tacky. Have you considered having it loop after so many seconds? Or making an interactive "playable" version, where the viewer can drag them into the houses, but the homeless quickly outpace the homes, just like I saw here?
It was a great length, and wisely chose a target audience.
Your question: "Hard, huh, helping the homeless?" immediately made the person think about and own the problem. You posed Samusocial as the solution well.
Let us know what grade you get!!