The Walking Vegetables: Radical Edition

You will need 5 RadRocks to unlock this trophy. They are dropped from bosses on Normal, in the Bonus Dimension, and you'll receive a bundle of them upon completing Too Hard Mode. They are the only item that carries over through each run. When you have 5, you will then need to locate a store. The levels are randomly generated so its location will vary, but there will be one one each stage, you just need to find it. There is also a chance it will require a key to open, so just make sure you keep one on you just in case.

When you’re inside the store, you’ll see a load of purchasable items and a bar in the back. In the center of all the weapons/items is a large purple container - this is the Radbox. Use the RadRocks to activate the box and it will unlock a random, new weapon for you. You will need to do this 5 times for one of the skills for Mad Skillz! so you will inevitably unlock it on your way to 100%.