Play with WASD and mouse. Shift to pickup items Q to drop items E to eat 1-3 to switch inventory slots F11 if you want to switch to full screen (with some borders to avoid scrollbars) Hints: If you get stuck early you might need to get rid of an item. If you push a box into a corner hit it with the dagger to reset it. Enimies and consumables respawns so you can always go back and grind for an upgraded weapon before fighting the end boss.
Searching for 04 is a js13k entry from nicklaslof