I'm guessing he's not a native English speaker.
If I understand it correctly it's a Java port.
Not a huge fan of Java for games.

Java isn't that bad for games when used with a high-performance framework like libGDX. LibGDX is basically a pretty good OpenGL wrapper suite for Java. I have used it myself for the Android port of Birth of the Empires.

Yeah, for a fast paced shooter like Blood Java sounds like an exceptionally bad choice.

As I said earlier, don't dismiss libGDX as just Java. And besides Java programs can peform pretty good on modern systems.
Besides, judging by the youtube videos it's pretty smooth.

I'm not a fan of Java for games myself but let's be honest here, it's complete non-issue in case of a title that used to run on the first generation of Pentium CPUs and especially considering that the main workload was the rendering which is now hardware accelerated.

But this is a complete rebuild rather than a source port, right? It honestly depends on how good a programmer this guy is.

True, we'll see.

Performance-wise libGDX is much faster than Unity, so there should be no problems.

from what I could dig up, he is russian.
so far it runs pretty ok, needs alot of sound code work.

Well, I fired it up, it runs great. It's largely incomplete (as Lord_Kane said, there's lots of audio stuff missing or off in terms of volume / attenuation) but I wouldn't worry about the performance. The game reports that it runs at constant 100 FPS in full HD. In other words: it performs MUCH better than the official Windows port of Shadow Warrior, lol.

Edit: Played it some more. Well, if he keeps it up this will be the ultimate way to play Blood, that's for sure. Awesome!

My main worry is that the mouse aiming seems to be suffering from the original Build engine issue where only one mouse axis could be processed per frame (and which was successfully taken care of for the DOS versions and in other Build game ports). It feels just icky. Hope he will fix that.

Edit 2: Oh yeah, also rendering of the Build engine's trademark portals doesn't seem to work yet.

Hmmm, interesting. Well anyway I think I'm gonna to hang out to see if an actual Blood source port gets made in the no-too-distant future (as we know whatshisname has the code but can't release it yet because legal reasons).

This is the BloodCM guy. BloodCM is Blood as a mod for eDuke32. I've played through the first episode, and it was pretty good. At the time, it wasn't fully complete, but now he has apparently completed not only the main game, but also the Plasma Pak expansion. So, you know, if you'd like to play Blood without the usual DOSBox hassle and you don't feel like waiting for the guy's complete engine re-implementation, try BloodCM.

Sound definitely looks like the main area needing improvement: on my machine I usually get an awful stuttering noise that starts when the initial logos appear and never stops. It does run smoothly except, for some reason, for a lengthy pause when changing the number of voice channels in the options menu.

Didn't have any stutter or anything like that but admittedly I did get some occasional hiccups during gameplay, apparently when certain sounds were played for the first time.