Is the the Plasma Pak supposed to just end or have I missed something? I killed 3 (4 perhaps?) Beasts, then pushed some skulls in the middle of the Training Ground and then pressed the button to end level and I got credits. No video, no text, nothing. Is it really supposed to be this way? It was quite anti-climatic.

Yup, it just ends.

Hm, that's lame.

It's a rushed ending I agree.

The whole Plasma Pak seems rather rushed (except perhaps the last few maps). The other official add-on (Cryptic Passage) is much better, even without new enemies.

I don't like Cryptic Passage too much. I don't like one particular feature. Enemies spawning out of nowhere. Basic game doesn't have this and Plasma Pak only in minimal amount. Here if you only pick up key or push some button and you have to go somewhere where you have already been you can bet rooms, previously cleared will be filled again. Rooms where is no way enemies could come there again "naturally".

Precisely why I didn't like CP much.

I'm not sure Plasma Pack was really "rushed". I think Monolith had an idea about what they wanted to do with Blood II, and needed to demonstrate that Caleb didn't completely wipe out the Cabal and they had a few tricks up their sleeves.

Monolith had a few maps left over, some of the maps were even in the Alpha, and we know they did plan on beast mode, judging on the content of the art files. I think they just went with what they had to make a few extra bucks with an add-on. No harm, no foul, more Blood, right?