"Synergy" trophy hint:
To unlock the Synergy trophy without anyone to play with, or if you want to do it alone, just play Mission 2. It is a flying mission so you don't have to move the other player.
Invasion - Clear Mission 1.
Diversion - Clear Mission 2.
Central Battery - Clear Mission 3.
Distress Call - Clear Mission 4.
Possession - Clear Mission 5.
Corruption - Clear Mission 6.
Biot - Clear Mission 7.
Hot Pursuit - Clear Mission 8.
Ultimate Weapon - Clear Mission 9.
Return to Oa - Clear Mission 10.
Synergy - Clear a mission in Co-op.
Just Getting Started - Perform a 20 hit combo.
Master Blaster - Defeat 10 enemies with Ring Blaster.
Blunt Justice - Defeat 10 enemies with War Hammer.
Demolitionist - Defeat 10 enemies with Hover Mines.
Favorite Pastime - Defeat 10 enemies with Baseball Bat.
All in the Wrist - Defeat 10 enemies with Blade Whip.
Locked and Loaded - Defeat 10 enemies with Gatling Gun.
Lights Out - Defeat 10 enemies with Piston Blitz.
Fan Favorite - Defeat 10 enemies with Rocket Punch.
Targets Acquired - Defeat 20 enemies with Missile Pack.
Big Beat Down - Defeat 20 enemies with Mech Suit.
Around the World - Defeat 20 enemies with Mace Storm.
Hal Knows Jets - Defeat 20 enemies with Jet Fighter.
Beware My Power! - Use Ring Surge 10 times.
What Goes Up... - Launch 20 enemies.
Get Dizzy Yall - Make Green Lantern dizzy 10 times.
Emerald Warrior - Complete the game on Poozer of Enforcer difficulty.
On a Roll - Perform a 50 hit combo.
Rank Up - Gain experience level 5.
There is Hope - Collect all 5 Blue Meteorites.
Mogo is Proud - Collect all 9 Green Meteorites.
Might Makes Right - Purchase all Attack upgrades.
Full Burn - Purchase all Ring Surge upgrades.
Complete Control - Purchase all Ring Power upgrades.
Willpower - Purchase all Construct upgrades.
Emerald Knight - Clear all missions on Emerald Knight difficulty.
Shut Your Mouth - Perform a 99 hit combo.
Not a Poozer - Gain experience level 10.
Big Spender - Purchase all upgrades.
Fear This! - Earn all Bronze, Silver, and Gold trophies