Toy Soldiers

Took me a few tries to figure out what worked here. Keeping tabs on your units and repairing or upgrading them when they're damaged is super important. When they're low on health it's a good time to upgrade since they'll go into their upside down mode keeping them safe and they then come back with full health and stronger to boot. Also, upgraded units can take more damage so it's easier to keep track of who's low on health. I typically repaired around 20% health - especially when that unit was under fire.

For placements, I tried howitzers on either side and one in the middle and found that they were too restrictive. You have to manage them too much because they can only fire the direction they're facing. They're useless if anyone get's beside or behind them. So instead my setup focused mainly on mortars.

Wait until the train passes the first go around. Often when I place units right away, luck of the draw has them getting blown up with one shot before the waves even start.

After the train's gone, start laying out your emplacements. I put chemical/fire in the spot closest to the tracks. This deals with the infantry waves as soon as they appear and slows them down for anti-infantry turrets. Another chemical/fire at the point closest to your toy box. I put anti-infantry turrets on either side of the large center placement. And mortars everywhere else. Upgrades mortars have good range and can fire in any direction. Plus if you take control you have the three shots to use. Basically, the turrets and fire handle any infantry and the mortars take care of everything else.

Get everything upgraded and just work on keeping them all alive. Losing a lvl 3 emplacement will kill you. Taking it out of action for a minute to repair will save you not only money but also all the time it takes to upgrade and keep a more powerful unit in action.

Go onto survival after finishing the campaign, wait for the train to go past or it will destroy everything you built. Build a "stokes" on the very northern small placement, and 2 "red stars" on either side of it, build a "howitser" in the middle big placement and a "red star" behind it. Go into the sniper tower and snipe as many as you can, repair any damaged placements when the train has passed. when you have enough place 2 "stokes" on either side of your "howitser".

Next proceed to place 2 howitsers on the 2 left over big placements.

I cannot finsh this guide as the random train of doom sometimes hits nothing and like now just blew up 5 of my placements.
Later on when it blew my northern "red stars" up i replaced with machineguns upgraded to level 3. Your best weapon here is the "stokes" i upgraded my middle howitser to level 3 and kept the other 2 at level 2.

Try keep all "stokes" at level 2 and 3 if you get the chance.

Remember... REPAIR! Example: Red star costs $600 to create, costs $100 to repair.

I got this on my first try on survival so if your having trouble tell me i'll try tweak my tactic.

I had many a trouble going for this achievement, mainly the armoured train kept destroying my placements.

The bulk of survival to begin with is infantry units so I would recommend placing a Red Star near the Toy box, and 37mm MLE infantry guns either side near the tracks.

Then save up money and place more infantry guns on the rest of the small placements. a Howitzer in the middle is always handy, as well as one to the left of the map. I had trouble on the right side because my howitzer kept getting blown by the train. So placed a mortar instead.

I had all my infantry guns upgraded to level 3 expect 1 in the middle, kept that at level 2, I took control of that to help defend the box. (A Handy Tip: use the camera to look in the direction you want the gun to aim when you take control of it. It will automatically face that direction and you can shoot without wasting time turning) my cannon's were level 3, and red star to level 3.

At one point air units joined so I destroyed my big right side placement and built Anti-Air to level 2, then when the threat was gone to level 3.

General Rule is to upgrade, repair and adapt to the situation as it is thrown to you. In the end I was able to survive for 15 mins. Plenty of time to land me the achievement.