You can earn an easy 10000+ points as soon as your mission starts without having to jump or roll by triggering the Mega Headstart which will launch you into the sky.
Beat ALL the standard plagues and the Neurax Worm on the Brutal difficulty setting to unlock the Necroa virus.
It is always worth keeping several Engineers out in the field with your main army as they come in useful when you come across something that could be captured.
Speed up the time it takes for your upgrades to complete by advancing the time ahead on your device. Just remember to set the time back to it’s correct value when the upgrade is complete.