This game is tricky, but there are tactics which will help:

1) Units change direction when they are in the middle of certain paths such as the corners and the T-sections. They will also change direction if they run into a wall, or another unit. 2) Scientists have a range of about 1 & 1/2 halls. When you see a scientist move, the effected zombie has about 3 seconds until they are cured into a civilian unit. 3) Some army personnel can kill zombies with 1 shot. 4) Isolating individual units quickly, and reserving them for later can help with the pace of the game. Level 5 is a real test of this tactic. 5) There are wooden barricades on certain levels which only zombies can destroy.

Controls:

Click on the walls to create a safe or unsafe path for the characters, or to block mercenaries and scientists. Use the A & D keys to move the camera around left and right. Use the W & S keys to zoom in and out. The keys Q and E rotate the view. The keys Z and X toggle the unit icon helpers. The keys M and P toggle the music on and off.

Press ESC anytime to bring up the save and load menu. The save option is available during game, and the load option is available in the ESC menu on the main menu screen. The the mouse wheel to move the camera up and down. Every level has an optional camera view.  Clicking on the change camera button will swap to a alternate camera view. Clicking the button a 2nd time will reset it back to the main view.

There may be updates for this game, depending on the public opinion on the concept. Anyone to purchases this version will receive new versions for free. Audio:

If the sound and music seems to not be working, it may be off by default. It can be turned back on through the main menu. Known glitches: If the hall areas get filled with too many units, they may glitch and push each other through walls, or push each other off the main middle path. So try and keep them all moving, just for long enough for you to reach the requirements, and hit the end level button.

The Android version is not on GooglePlay anymore, and is slightly different to the other versions. 

The old version of the game is available, however the rules listed above may not apply. IE, in the new version the civilian units look almost identical to zombie and the controls are different. 

Facebook page:

https://www.facebook.com/Zombie-Quarantine-Game-747915678886561