Well, I played your map and the short version is: enjoyable and looks good. The first part was tight packed with action and the second part had some interesting puzzles. The scenery was not very original but it was well worked out and did not look sloppy or unfinished.
I had a pretty decent run until I got totally surprised by the old trick of flaming barrels rolling of a tiny elevation. The margin for error was rather small there. The Combine metropolice responsible for that were just crouching behind no cover which appeared rather silly. Never had a more literal example of shooting sitting ducks.
I had a real close encounter with death at the part where you have to break through the wooden barricade at the train track. Either I skipped too many Combine but I had the feeling they kept popping up from everywhere – not a bad thing though. The metropolice are quite a pushover in small numbers.
Next I come in the sewer part which appears to be a deserted rebel hideout at the same time. It is ridiculously close situated to a Combine station but ok

. Did the Barnacle trick good in one try but what if the player shoots it before using it to get on the platform? Was that supposed to be completed by getting grabbed by a Barnacle?
Starting the engine was new and well introduced to the player. I had no doubt what to do when I encountered the second one. Due to my own stupidity I almost committed suicide trying to spectacularly grenade the barnacles off the ceiling. With the abundance of explosive barrels throughout the map I found myself questioning why fate – of all time – would leave me without one at that specific point.
In the end I got rewarded with a nice zombie slaughter. I did get completely caught off-guard by the fast zombies at the very end – probably because I was in the wrong location at that moment. I certainly was disappointed that I couldn’t grab the SMG from the dead rebel’s hand but it looked nice.
Overall a fun play – thanks for sharing. I send you the email with the recorded demo. From 7-8 minutes on you can enjoy watching me almost 10 minutes trying to solve the second engine mystery so sorry about that. I really couldn’t figure it out although in hindsight it was reasonably obvious – I’m a bit dense at puzzles.
Oh, and just the tiniest bit of story would be sweet. If only a textmessage or radio transmission telling me where I am or why.