I did not have problems with the darkness, atleast gave good reason to eat carrots and spam maps for possible sightings of enemies
But if you have problems seeing the enemy, I suggest you use that 3d Map, and use it often. It shows all enemies in your LOS.
This is rather hard to explain or to give some walkthrough. Myself I clear the road MG near the start and secure it, then I take out that AA gun near it, and use the railtrack area to sneak and to kill enemies if needed (I once stabbed half of the enemies around there til I got caught). Also, clear all AA guns you can find.
Then, just go far right, so that top MG near that station can?t aim to you. Then you just need to rush quickly in and kill every enemies, make sure someone is watching the entrance so the enemies outside cannot shoot to your backs.
After that, blow that power plant, or what it was? Long time since I played it
Then, make sure your every man, expect one, is near that road MG what you captured. Then set up around 30s - 1min fuse to TNT, get your last man there, secure a truck, wait for the bombardment.
When bobardment is done, drive the truck back where you started. You find a welcome ceremony in there but just drive over them and that?s done.
So, in simple, secure that truck area and eliminate that MG42 nest. Then, eliminate AA gun near right, and use the far right path to take the rest. Then, eliminate all threats around the railways and proceed from far right into the station. Secure the station, the MG tower, set up charges, wait for the show to begin, wait it to end, get a truck and drive to the start, also over the Germans which are not pleased what you just done.
This takes about 20 - 50mins with couple of saves when you get the idea.
And for note, H&D Deluxe is old so you can expect some similiar graphics, faces etc all the time
And for H&D2 co-op, well public co-op game will not work, but myself, I usually play with 2-3 friends and try to use some tactical approaches etc. Gives more fun out of it.