This map is really great! The combine mounted guns, mines, turrets and mortar system are really neat and it's a fun play in singleplayer.

However, if you were to add to this map, perhaps an interesting addition could be some sort of "extreme mode" that makes enemies spawn more frequently or in larger groups; maybe there could be a few underground tunnel entrances that they could come out of as well.
The map becomes really easy in multiplayer, partly because more gun = win and also because when I play singleplayer I don't shoot the dropships down like my teammates did.

I also have been looking for mods in general that make combine stronger, they're the bad guys- but it does feel like they're a bit underpowered compared to the resistance.
If anyone knows of some good mods like that, please send them here!