To create a game with this much promise in just seven days is a feat to be proud of. However, as with everything else, further editing can always help. Take my previous comment, for instance. After rereading it, I realized that there were a few places I misspelled simple words that could have easily been avoided and corrected. In addition, had I dedicated more time to considering my words, I believe I could have refined half of what I said to a more acceptable length. With your story, now that you have the time to review and think about how you'd like to go about your planning, it's completely understandable how not everything would meet your satisfaction. But that is exactly the purpose of a first draft: get your idea down so that you know what you're working with before you can decide what has to be fixed. I'm not a game designer, but I do love writing and reading stories. That's why I believe I can say what I am with confidence.
In response to your final comment, I don't think that's necessarily a bad thing. Just as it is unrealistic in life to have everything turn out the way you want it to, it's impossible for every story to have a happy conclusion without being forced. And with this ending, rather than a definitive happy/bad turnout, you've made it a little more vague. It's left up to the readers to decide exactly how this will affect Sam based on the thoughts they've drawn throughout the story, which is why you seem to have found yourself with a divided review over what happens after. These kinds of endings, though not always welcomed, are perfect for inspiring the reader to think. Personally, I do prefer a happy ending, but I'd rather the ending make sense more than anything else.
Since you say that you would like to expand on the story, I think I'm going to reread this one again to see if there's anything in particular I think might help. Let me know if there's anything in particular you'd like an opinion on.