**Edit** Update changed it so restart puts you at the beginning of the game!
Must be local co-op or share play for this trophy.
Do this on rookie so enemies and bosses die quicker.
Original Solution below
Still rather simple to do with 2 controllers and a rubber band.
Must have 2 controllers!!! you can die just restart level that you died on and continue on! Also able to be done solo and rubberband the R3 button on the second controller the other way you are facing.
Best done on rookie, i saved all bombs for the final level which takes care of the boss pretty fast.
When you boost your partner boosts with you so they are invicible until you stop. You using your boost doesn't drain theirs so your partner can boost immediately after. This helps from getting out of tight situations.
Dont forget to use your overdrive! And good luck!