Tip 1: Defeat the Boss on floor 1-4. Do not enter the portal that leads to the next floor. Instead, remain on that floor and kill yourself with grenades or by jumping in spikes or lava.

Tip 2: Explore a floor and find a challenge room, danger room, or a room with an environmental hazard or trap. Kill the Boss, but do not go through the portal. Instead, return to the previously discovered room and die to the trap or hazard.