Nuclear Throne

First, you will need to unlock Robot by reaching 5-1. This is apart of natural progression in the game. After beating Big Dog on 3-3, you will just need to make your way through a crystal cave.

Mainly, just try to stay back away from enemies as much as possible and pick people off. Play it safe and work yourself through each level without putting yourself in danger for whatever reason. 5-1 is where it starts getting much harder, so you will make it eventually.

Once you unlock Robot, start doing runs with him. The earliest that you can find a hyper weapon is 3-3. From 3-3 onward, it is possible to find a hyper rifle. Once you find one, pick it up and press with it equipped to eat it.
This will unlock this achievement and Robot's B costume.

(The other 2 hyper weapons do not start showing up until 7-1 and 7-2)