X-COM: Apocalypse

First week
In the first week, ammunition is scarce. There should hovewer be enough to go around unless you waste it. Take every opportunity to conserve ammunition possible. A few explosive grenades would be a good idea to use. Put some effort in bringing down at least one of every type of UFO that appear. Also, finish the bio-transport module as soon possible and put it on a craft, the better you can start bringing in live aliens for research the better. After a bio-transport module has been created fit it on a craft and try to capture live aliens. The way to do this is to attack a live specimen with a stun grenade or stun grappler untill it falls uncouncius, and then finish the mission before it wakes up. Throwing more stun grenades will keep it uncouncius for longer.