The description is a little confusing. What it really means is that your ship must survive for 9 minutes without being destroyed. You may, in fact, miss enemies and it will not void the trophy. You must, however, earn the trophy in single player mode.
It is most simply done on Easy Mode where you do not have to worry about employing bombs. The game will automatically detonate a bomb when the ship is in danger of being destroyed. It is also easiest with the Ghost Ship's wide angle shot. Concentrate on survivability. Alternate between the regular shot to take out all the weak enemies and the focus shot to clear a path, take out the robust enemies, and generate the tech orbs required to fill the bomb gauge and manufacture additional bombs.
The nine minute mark occurs just before you reach the 3rd stage boss. If you survive till then, the trophy will unlock. Moreover, if you have the skill to unlock this trophy, you should have enough skill to continue on to the end of the game without using continues in order to unlock: