Killing Floor 2 doesn't come with a tutorial. So, you might find your first time playing it daunting. Here are some tips to help you conquer the game's Survival mode.
1. Aim for the head. As you progress in waves you're going to be absolutely swarmed with enemies, and there isn't time for you to run around pumping tens of rounds into their abdomen. You'll want to learn how to quickly hit enemies in the head to finish them in a timely manner.
2. Stock up on armor and ammo. Armor keeps you alive, and ammunition is in limited supply. At the end of the round make sure to stock up on both at the Trader. This can mean the difference between life and death.
3. Buy a Medic Pistol. Every class can equip the Medic pistol, which offers you a way to heal teammates from range. Purchaseable in the Field Medic section of the Trader menu, it costs only 200 dosh, and has a weight of one. All teammates should have one.
4. Use your sidearm or melee weapons on trash enemies. There are quite a few enemies that are easy to kill and don't really require the firepower of your main weapon. Since ammunition for your primary firearms is scarce and more expensive to replace, you will want to get used to using pistols and melee weapons on weak enemies.
5. Play a Commando or Field Medic if you're new. These two classes are specialized in the two things you're going to spend most of your time doing: shooting enemies and healing teammates. The Berserker and Support are more situational.
6. Stay with your teammates. You can't win alone no matter how good you are. Always be aware of where your teammates are and stick together.
7. Don't walk into a corner. Movement is imperative to your survival. You want to be able to kite enemies around structures and not be boxed in. So, think carefully when you backpedal to ensure that your positioning doesn't put you in a bad situation.
8. Heal yourself. You can press Q to heal when damage is incurred. You can only do it every so often, but it's powerful when used at an appropriate time.
9. Carry multiple weapons. By the time you reach the final boss you're going to need a ton of firepower. One weapon just isn't going to cut it. Don't hesitate to pick up additional weapons.
10. Scavenge the map for resources. There is armor and ammunition scattered around the map. Finding some will save you dosh to spend on new weapons.