Pretty impressive! The 64x64 resolution actually helps the mood. Having to use the command line to scale the window is... not preferred. I found myself preferring keyboard over mouselook, which I previously thought impossible.
I like the limited-color aesthetic. The graphics look crisp because there is no texture interpolation, but this makes things like doors and enemies not stand out from afar. If the doors were green, for example, you could identify them from far away.