So I've been working on this game for a good bit, and I feel comfortable with what I'd consider to be a sort of teaser or demo for what would be a much longer game overall. Is it still acceptable to upload saying that it's a demo? or is that not allowed?

Depends on how big the demo is.

The is a games feed back thread on here, if that's what you want.

Just make sure you have a description on all your "looks" for the first few objects. I don't know why they look at that in particular, but they do....

There's a Work in progress thingy to click on during the publishing process.

...and there's a Sandbox category, which I believe is for ...

What is that for?

@XanMag!!! What's the difference between those two methods of publishing?

You can also leave the game unlisted when you publish it and create a post in Game Announcements and Feedback with a link to your page. We'll still be able to play it, but only with the link you provide.

Work in Progress = authentic category
Sandbox = default category they put miniature, unpolished games in. I'm not even sure if you can select that option...!

Well, it's 32 pages in total, and it's done in the style of a gamebook. So as for the length... That really depends on how fast you read, which ending you get, etc. The Work in Progress category seems to fit it best, right?

Yes. Toss in WIP. Sandbox is kind of for the... clunkers. Clunkers like Furby McQuack. :)