Oooh, I really like how that third picture looks. All the others aren't that great.

Keep up the good work!

Dude, if you just want feedback on how your sprites look, don't submit them to the database. That's for completed stuff that you want available for the masses to use.
What you want is the Official Original Graphics Showcase thread found in the Developer's Exchange forum. Add a post with a picture of your sprites and ask for feedback; chances are that you'll get it. I, for one, am following that thread and comment whenever I can. After you've received enough feedback and are quite certain it looks as good as you want it (and still want to share it with others for them to use in their quests), then you submit it to the database.

Now, here's feedback regarding this sprite:

• Nice colors! However, I think it breaks the rules for how many colors to use for GB-style sprites, but it's up to you if you want to follow the standard or break the mold. (Be advised: "breaking the mold" comes with costs; you might receive negative criticism.) Correct me if I'm wrong, though, 'cause I haven't played any of the Oracle games.
• I get that you want it to be ancient, so it makes sense if it doesn't look exactly like a Native American tent (which has a constant slope, not two different slopes, along the sides). I could see a stone structure looking like this. However, I don't get why the bottom of the sides have a little protrusion. Are you trying to make it look like there's a "lip" that goes along the entire outside bottom of the tent?

Just to be fair, I'm giving this a rating of 3. If it's changed/improved, I might change my rating. Right now, I'm leaning toward a lower 3 (like 2.75).