The progress is going fine, however I rather not give percentages or dates since is kind of difficult to tell when the final demo will be ready. However, if you mean the final completed game, then it will take minimum 2 years I think.
It is really difficult a lot of the time, and there are different dev styles. Do you figure it's two years from now, or two years in total, or you'd rather not say?
It's minimum 2 years from now, it's planned to take 3, but honestly, is kind of unpredictable, anything can happen and it depends a lot of if all goes smoothly or there is difficulties along the way. So I rather just leave that stimated time as a posibility.
