The best AT units are half tracks, but the combined upgrading costs a total of 24 tp. M3 ATs are far too slow to be a life saver against multiple tanks, and mortars can only take out weaker tanks on direct hits. Your best bet is to find the rare bazooka that isn't being fired blind and backwards.
More than new guns, quests, challenges, more than anything else- this game needs a "repair all" or "heal all" option in clinics, hospitals, and repair shops. When I have say ten carts to repair, it is very mundane to do.
To save press the "X" below the name of the town (starting town is Poca Cosa) which will lead you to the world, where you can find new towns, fight robbers, die from dehydration, etc. if you look in the bottom right there is a wrench with CPT. written below it. Click it and then it will bring up the game menu. It will also prompt you to save before battles. Make sure you go to the main page and check out the tutorials if you can't figure things out for yourself :).
Here's what this game needs for realism: Longer reloads, lower accuracy, faster fire rate, more damaging bullets, far less tanks (some beaches had no tanks at all to make it to the beaches), slower guys, and then it will be realistic.
SPOILERS: 4/5 My one beef: One of the German Nazi zombies was carrying the M1A1 Thompson Submachine gun. This was the American weapon of choice, Germans would use an MP40 unless their life depended upon using an American weapon.
This game has serious problems. You can't set any formation, and there is no queue for buildings, you have to make them one by one. In most games when you build a wall, you decide where you build it and your engineers build it over time. In this game you build the wall ONE BY ONE, then place it. This is with buildings and is tedious as well because instead of buying and placing you are buying, keeping an eye on it, and then placing. I understand the units not automatically making a wall, but being able to set two by two's would be nice. It's not even realistic, if I have 10 tanks they will move in 2 columns and five rows not 1 column and 10 rows.