And it's amazing. The detail is jaw dropping. If you love walking around video game recreations of historical things (like in L.A. Noir, for example), then this is for you. The developers have a team of consultants, so everything in Honor and Glory is as historically accurate as possible.
There isn't much "game" there yet. Rose hasn't gotten her night vision goggles yet (yuk yuk). Currently, it's kind of like Myst or Dear Esther, in that you're just taking in the sites and sounds.
But Demo 3 gives you a really good idea as to what they've been working on over the last two years. And when you compare it to the work that was done on Demo 1 and Demo 2 (also available for download), you can see that they're making real solid progress. The authenticity from Demo to Demo has only been increasing. And the only thing that Demo 3 is really missing is other people to interact with.