Sorry for the delay, but the latest build is finally available for download as the demo. You can find it on the right hand side of the store page.
A couple things to note since I haven't gotten around to a tutorial:
You now remove objects by holding them and squeezing the grip button for half a second.
If you are not holding something, you can squeeze the grip to drag the play space around you.
Sorry this isn't more detailed, but I haven't slept for completely unrelated reasons.
Please feel free to post feedback and/or questions here.