Play Sift Heads 7 Ultimatum unblocked. The crew is back once again in part 7 of this epic action/shooter. This time the game is being pursued by the coppers while they face their deadliest enemies. Sift Heads World Act 7: The Ultimatum unblocked is rated T for teens. How to Play: Use the mouse to move around and shoot your opponents. Reload with the R key and press the space bar to equip new items.