Zombie Shelter is based around upgrading your base then killing the boss to win. You need resources and skills in order to complete both these objectives. Also money is pretty important for killing the boss. There are mini bosses that spawn later on in the maps also. The main the boss is the guy in hole, please let this be obvious.

Some people join my games and they are just speechless. Please talk and update your team on what you are doing. Communication is key to victory. In 4-player team you need:
1 Tech
2 Collectors
1 Survivor/Fighter
Always check, that is there all of them, where Tech are most important, and Collector.

Skills are very important to winning. Also one of the areas scrubs screw up in. As soon as you enter the game with multiple people figure out who is doing the Technology skill tree. Who ever is doing this skill tree is building everything for the entire game. The blue skill tree in the middle called Scavenger is also an important role. They are the people that collect resources for the builder. They do not build never build unless you are a tech please. All these stupid people keep building without being the builder it is so annoying. Anyways, the next skill tree is Combat. These people protect the base from the mini bosses and Juggernauts. They should also follow Scavengers around so they can kill the zombie turrets and tough zombies for the scavengers to collect the goodies around them. Always figure out who is doing what skill tree and do that role properly.

This entire section is about the Tech tree. If you don't know what you are doing it's gg. Some people have different priorities as to what they build first.
A good way to play as tech(if you have good collectors) is to build: 3S.Generators - Recover Faciality - 3Werehouses - 4Turrets - Shelter lv.2 - 1M. Generator - Comm. Tower - Shelter lv.3 - 6(/7)Enh. Gatlings - Concentrate Rafinery - 1Enh. Mortar - Enh. Gatlings for rest of energy.
To do this way, we need to maximize building skill, in "Technical" part, middle skills with Wrench on it ('Building Skill'). But remember - to build Enhanced Gatlings and Mortars, you need Technical Crafting skill makes you able to craft 'Enhanced Tower Parts' and 'Public Resourece System'(very usefull).
Now place - 'Recovery Faciality' should be standing in front of enterance to shelter - it blocks zombies like barricade, but they dont attack it that much. First 3 turrets - close to place where ZM's spawn at night (Shelter->Left->Stright->Left-<Next to back wall. and 1 Turret in front of shelter, also under wall. Gatling later should replace them. Mortar should stand next to white car close to 'Middle' (where Juggernaut spawn). All of these, should make night peacefull (without small Zm's) and stabile cash income for Tech.

Remember, that game without Tech, are lost game in night 5th /10th. When you join someone with shelter lv 1, first ask "Does we've got Tech?". If they already have they need Collector. Do what you can, just dont let shelter get destroyed and build everything needed.

Collector have almost easiest work, but it's still 2-nd most important class in Zombie Shelter - they focus on Survival Skills Tree. If You are Collector, You build 3 times First Harvest Skill (Survival Middle lane) and once Advenced Harvest Skill. Advenced harvest gives You can collect adiatonal some Iron and liitle Wood from diffrent obstacles - cars, lanterns, trees(dafuq?), containers. And of course much cash from ATM's (Cash machines).
After taking harvest, take 3 times HP Enhance from 1st tree (Fight tree? Militarry tree?) Later upgrades dont even care, just stay alive, collect as much as you can hold up, and win :D

This class are for start preety useless and not worth - but later, only he can win game.
He focus on dealing Dmg, defending collectors, and defending base. You shoukd take smg 2times and hp once on start. Your destination is last active skill of fighter tree. Much AoE Dmg. Your "mission" is to walk around map to kill Deimos and destroy Poison Turrets - you can gain cash only from that.
He is collector, but not at all - his destination is Survival active skill 'Hide' and some weapon that deals lots of dmg in one shot (e.g. Smg - Newcomen, Rifle - any sniper...). In 3 rushes, he should kill Last Boss on ZmShelter. It's not hard work, but you can't take it at first if you don't have collectors. But later, anyone can reset skills ;)

Please comment if I missed anything important that is not opinion based. I would not like comments on my build path for techy. Also, I think this game is amazing and I am happy i can support the devs. by buying things in the store. Please continue to make events, weapons, missions, and people please.