I have to say I enjoyed this demo, the few puzzles you had in it were not too difficult to figure out - although the instant kill on the electric water wasn't something I was expecting and tried to just 'book it' across lol.
One little issue I did have is that the bridge part where you need to hold out for it to come down, maybe add a 'ding' or something to let the player know its down (if you already have one then I guess I didn't hear it over the sound of gunfire from 9 different sources lol).
Also some of your traintrack props need to have their shadows disabled (Screenshot 3 and more noticeable in the final heli battle). Speaking of traintracks, the interior portion warehouse area would do well with an initial spooky ambiance while the player navigates around the cargo containers before triggering the combine repelling from the roof - Nice touch! But I didn't know where they were first firing at me from till the rappelling line noise started so maybe start with an explosion + glass to get the players attention.
Overall it was quite a fun demo with some colour commentary from myself during the bridge part lol. Really get that cornered feeling and there really is no cover from that damn helicopter :D
Summed up I would say more music ambiance in the quiet sections or more interesting soundscapes, either one.
Very nice mod, I look forward to a final release.
Uberstyle still progressing...