the box

The final and most punishing Box achievement. To earn "the box" (all lowercase), you must complete every chapter on Impossible difficulty with every available class. Impossible is the highest difficulty in Mewgenics, where enemies are overwhelmingly powerful and even small mistakes are fatal. This is the rarest achievement in the game. Completing this unlocks "the box" trinket (Steven set, Very Rare), which lets you find and equip a random item into one of your empty item slots on use.

Tip: Impossible difficulty is designed to test absolute mastery. Every class needs a perfected strategy, and you will likely need to rely on the best item combinations and deep mechanical knowledge to clear each chapter. The trinket reward is part of the Steven set and provides on-demand item generation, letting you fill empty equipment slots mid-run. Earning this achievement is the true mark of a Mewgenics completionist.