Yes, they are allowed. Whole purpose of the Jam is just to get your games playtested in their current states (as in, the moment they are being tested). There are no restrictions in what kind of games or in what state they should be.
If there seems to be need, I might set some rules, but currently there are no rules.
As long as you have a game that needs feedback through playtesting, feel free to submit it, and you can submit it to next jams too, even in the same state.
You may also update your game as much as you like. This is not a competition, just a way to get feedback. That basically this is not really a Jam, just using Jam system to have easy way to get playtest and feedback.
