The latest Stygian Sentinel update from OtherSide Entertainment announces that the first prototype of the game will be released to even more backers, although there is a catch:

This Prototype build is meant to provide an early peek at core game mechanics, like physics interactions and magic. In it, the player is taught the fundamental rules and given a series of goals, then let loose to find their own means of solving them. It’s been fantastic seeing all the inventive solutions that fans have come up with. This is exactly the kind of experimentation that we intend to foster in Underworld Ascendant.

Soon we’re going to make the Prototype available to even more fans. For everybody who pledged at the Pioneer tier and higher, you will be able to get a $5 Add-On through that gives access to all future versions of the Prototype builds we release. This Add-On will also come with a $5 credit towards any future Add-ons or additional Pledges.

We’ve already made a host of improvements to the Prototype, based on fan feedback and bug fixing. We intend to continue for many months to come, so you’ll get to see first-hand how your input makes a difference.

We’ll be sending an email to eligible backers shortly when this Add-On is ready.

The Pioneer tier referenced above is, I think, the $27 USD Pioneer’s Progeny tier. So that’s good, if I’ve got it right: basically everyone who has backed Underworld Ascendant at a level that includes a copy of the finished game can get access to future prototypes via a $5 USD add-on.

This Stygian Sentinel update was also the means by which OtherSide teased that they would be making System Shock 3, although of course that secret got out ahead of its planed revelation.

Additionally, you can find Christmas wishes and gaming recommendations from the OtherSide team at the end of the update.