Iron Grip
Very rare3.1%ObjectiveOptionalMulti-player
Co-operative
Never lose a cube in Chamber 6 of the Mass and Velocity co-op course
Get through Chamber 6 of the Mass and Velocity course without ever losing a cube (letting one drop into the goo or a pit). Play it slowly and deliberately, agree with your partner who's carrying and placing what, and if a cube goes over the edge just restart the chamber and try again. See its sibling 