Looks like the Bloodborne Alpha had quite some secrets hidden under the hood, and YouTube user Sanadsk brought them to light.

The third video below shows rather heavy spoilers (which is why it's at the bottom), so don't read further unless you don't mind. You can watch the first two videos, which are safe, but stay away from the third.

We get to see a new area, an armor set, some glitched invisible floors probably due to the fact that the zone wasn't meant to be visited and two boss fights.

One, a giant boar, seems to be a miniboss, while the second is "Priest Gascoigne." Gascoigne is the hunter that helps the hero towards the end of the alpha level, but apparently he has a secret dark side, and therein lies the spoiler.

On top of that (literally, since they're the first two videos) we also get to see two more great gameplay videos in shiny 1080p, courtesy of user Prodigious.

//www.youtube.com/embed/oQOvPgoUg7k?rel=0

//www.youtube.com/embed/-ACWP6akV_s?rel=0

//www.youtube.com/embed/PCc8nrTEKv0?rel=0

[Thanks for the tip: Mark Beast, Sephiroth_GR_]