Supportive Squad Trophy
Complete 50 missions without anyone being downed.Note: You don't have to survive 50 consecutive missions without dying so don't panic if you do happen to go down/die at any point.
This trophy is annoying but still very doable, even with bots so see below for some tips:
Play on Casual difficulty: Casual difficulty is far more forgiving than Standard difficulty and a complete cake walk compared to the others, because you will take far less damage from attacks, the enemy A.I is less agressive and friendly fire is disabled so you can't accidentally kill yourself or your Teammates.
Find a Kit and build you're comfortable with: Experiment with the different Kits (Gunner, Demolisher, Technician, Doc and Recon) and find one you're comfortable with, then develop a build that works for your play style.
Don't run!: One of the biggest mistakes you can make in this game, is rushing head first into an area without thinking about the potential dangers so take it slow, maintain situational awareness and prioritise your targets.
Replay Mission 1-1: Mission 1-1 "Priority One: Ingress" is the shortest and easiest one in the game, which makes it the best choice for this trophy.
Be careful which Challenge cards you activate: The Challenge cards can make your life a lot easier when going for this trophy but can also wreck your chances if you choose the wrong one so if in doubt about which one to use, don't activate any of them!
Turrets are your friend: On Casual, Standard and to a lesser degree Intense, Turrets will save your bacon during the mandatory Swarm battles so bring as many as you can carry, then deploy them in a way that covers all the possible attack vectors the Aliens will come from.
Prioritise your targets: The elites and other special enemy types (e.g. Spitters and Bursters) are the main threats you will face so take them out ASAP, before they have a chance to decimate your team.
Once you have successfully completed 50 missions without anyone going down or dying, the trophy will pop during the post-mission results screen.