Here is the full list of all 20 Gravity Crash trophies - there are 19 bronze and 1 silver.
Beat the recommended time on 10 levels
Gain a score of 1,048,576
Finish the single player campaign game
Find all gems in every level
Activate every node in the game, including those in secret levels
Collect all artifact pieces
Collect a total of 10 purple gems across different levels
Create and publish a level then have it rated by 5 users
Kill 255 gun or missile turrets
Unlock any secret level
Rescue 50 stranded crewmen
Have rear, side and 3-way fire simultaneously
Let a homing missile chase you until it runs out of fuel
In manual shield mode, save yourself with only 5% of the shield remaining
Complete 'Norova' level without refuelling or dying
Defeat any boss
Refuel your ship after the fuel depleted warning message is displayed
Find 5 user created levels you like, and rate the creators
Complete 'Vectora' level without firing a single shot
Complete all training lessons