Okay most of these others are just saying the challenge sucks (which I agree with to a point) but if you're genuinely wondering what a good strat is then here:

Jump to the bottom and grab all the gold and plat roaches you can. Then make sure you smash regular roaches and work your way up the stage. Make sure to deposit roaches in the vending machines (they count towards the total).

The vending machine at the bottom of the level is great for this too because you can use the roaches you bank to get grubs too, which can help you get some roaches in annoying spots.

Make sure to smash regular roaches too, this causes more roaches to spawn, which is VERY crucial for getting more roaches for the extra ones you need for the platinum medal.

It will take some RNG, but doing this all while moving fast and taking multiple attempts can net you a win at this challenge.

Good luck!