Zombie Apocalypse: Never Die Alone

This solution requires you to have maxed out characters in singleplayer. If you do, this achievement is a joke.

I don't mean any offense to other guide posters, but I really don't understand why they're making this sound like any sort of challenge, because here's what you do with maxed out characters:

* Load up Survival: Classic.
* Put the controller down and let the AI kill everything.
* Make sandwich as the game plays itself.
* Pick the controller back up on waves 7, 14, 21 and 28 to make sure you survive. Just keep tossing teddybears, boomboxes and turrets and heal only when your team is about to die. There's basically no difficulty difference between 28 and 7, so don't worry.
* Keep an eye on the TV to make sure no freak accident occurs. Heal, toss a teddy and plant a turret if it does, then go back to your sandwich.
* Win achievement.

You must complete the story first then you can select classic mode. But before you do this you should try to level the weapons, bait, speed, and the special pwnage abilities for each character. Once you have done that everything will be easy. The only thing you have to worry about is the dynamite zombies. The reason for this is they come in huge groups at you and they can take a huge chunk of your characters health if you are not paying attention.
The C-4 teddy bear and the boom box will be your friends. Those two and sentry gun can keep zombies off your back while you heal, or revive one, or all of the characters. The mash-up weapons will help in the higher levels. The chainsaw is the only mash-up weapon that i find useless in the higher levels, so i would say dont use unless you have no choice. Once you complete day 30 achievement unlocked.
If all 4 of your characters die then that means you have to start over at day 1. Good luck.

If your going to vote negative please say why before you do so i know how to fix.

After you beat the story mode, Survival: Classic unlocks as well as Blackout. This achievement is for Classic, and you must survive 30 days of it (though you can keep going beyond 30 days if you like).

I chose Father Bill for these, as your pwnage meter increases based on the damage you output. What this means is that usually whatever character you use will gain pwnage faster than the rest.

I also suggest doing this with 3 AI characters, as their auto-aim is spotless.

The stage setup for both survival modes is Chapters 2, 4, 6, 8, and 10 (from story mode), looped infinitely. Chapter 2 was the downtown level, Ch 4 was the level with the plane hangar, 6 was the level with the mechanical bull, 8 was the power plant level with the 3 switches, and 10 is the last level of story mode. Once you complete a cycle of these 5 levels, you'll go back to the downtown level while continuing your survival days.

Every 7th level(day 7, 14, 21, 28) is a Kamikaze zombie level, so please be on alert for this. This is also a good reason to be playing as Father Bill, so you can build up your pwnage faster and keep the healing going. I tried using the donut to help with this, as well as the mechanical bull (when I reached the appropriate kamikaze day) but also kept my characters moving when need be. Every 7 days are usually the only levels you need to worry about, with sometimes bigger Damned (like the puke spewing ones or the big aggressive ones that throw you around) showing up on random days, but they didn't pose too much of a problem.

You can choose to walk away from the non-7th days, but I advise that if you do, you at least rubberband your right analog stick. I noticed that when you don't shoot, your AI will only shoot when zombies are extremely close. This could definitely lead to being overrun. If however, you're shooting, even if you're not moving, your AI will shoot at zombies across the screen. If your right stick is always pointing out, therefore making your character shoot, your AI will always be shooting as well; they won't wait for zombies to get close to kill them.

I also suggest you max out your stats before doing this, as neither of the survival modes increase your stats at all (I tried doing this before max stats and it didn't increase any stats), so there's really no point to attempting these achievements until you max your stats (since your stats carry over to survival, you'll be completely buffed if you max everything first). Also having max stats will make survival mode a breeze.

Also make sure to take advantage of your teammates' abilities to help speed things up. Feel free to use the boomboxes, c4 teddy bears, and even your teammates' pwnage abilities when they build up.

Most levels I was averaging about 2 minutes and 15 seconds, with some levels going as fast as 1 minute 25 seconds.

Some things that weren't included in the first solution (at the time of writing 01/23/12).

-The AI are surprisingly helpful. After doing this with 2 human players + 1 AI and failing at Day 7, I can say that you + 3 AI is the best combo. You and another human player who knows what they're doing might work well too, haven't tried yet though.

-Using Jeremy seems to be the way to go for this mode (and blackout mode), since his automatic weapon packs damage/range/and firing rate all at once. You'll probably figure this out by the time you have finished this game and are starting this mode but just a heads up in advance that using Alma, Def Money and Father Bill will be a lot slower and you have a much greater chance of failing on the dynamite zombie waves (see next point)

-Dynamite zombies are mixed in with regular zombies every 7th day (on Day 7,14,21,28).

-C4 Teddy's, Mashup weapons and Alma's Sentry gun are definitely your buddies but Father Bill's radiant circle of rape is also CRUCIAL in dynamite zombie waves. If your guys are getting low or a portion of your team is down and you got Father Bill up with PWNAGE available, pop it and it's pretty much a free get-out of restarting card where you can just run around reviving everyone and healing them up to full. Oh yeah it also does damage to any undead in the circle as well. Double bonus.

-This achievement CAN be extremely frustrating and time consuming. 30 levels. An average of 2 minutes per level (and I'm being nice here it's usually 10-20 seconds longer) without taking load screens and menus into account. At the time of writing I have not yet obtained this achievement after carelessly screwing myself over on Day 21. Give yourself at least an hour and a half for this achievement and don't rage too hard if you fail (can't imagine what I woulda done if I got killed at 28).

Anyways, there's my contribution to the TA community today, and if anyone wants to help me out with this one since 2 good players might make this easier, please send a PM here or XBL.