I had a chance to play this the other day, and I think it's quite impressive what you pulled off here with the logic entities. The environment itself is nothing to sing praise about, but certainly the fun arcade-style gameplay you've setup with the whole buying system is pretty original.
I've seen this buying system implemented before in different ways for other Source games, but this one, with all the different options there are, is really the most impressive I've seen. One could really sit here and play this map for hours ... and hours; for me it was too overwhelming. I wanted to see some of the cool features you implemented but without all the time to involve with it, so I decided to cheat and turn on god mode and add 'impulse 101' as a hotkey and go around shooting an infinite number of rockets at zombies in order to rack up the points faster. I'm not sure what kind of individual will sit there and play the entire map for longer than an hour with the intended non-cheat method and still have fun. I think for the system to keep the attention of more players, you should reward bigger scores for zombie kills earlier on in order to allow players to obtain more interesting killing devices earlier, -but that's just me.
Nevertheless, this map was quite fun to play, and I enjoyed a lot of the cool unlocks. If anything, I would have turned this map into a kind of more coherent setting, rather than with seemingly random open rooms with zombies spawning behind your back; perhaps give reason to each space, and make it look like it belongs somewhere. I suppose I would have added some kind of empty stadium around these rooms (add it in a 3D skybox for performance) and make it seem like a life or death game in the world of HL2. Perhaps add some non-accessible buildings in the distance, or somehow give relevance to the places.
Either way, the map was still pretty fun, and it held my attention for a good 45 minutes, even though I cheated :p. I still had a lot of fun anyway.
Keep up the cool feature-mapping
