I spent a large chunk of my time with the game on the first available map, Hell. Entering Purgatory, the second map, requires special keys that can only be obtained by progressing far enough with the final boss battle in Hell (a three-headed Lucifer). While I managed to snag some keys, not many players from the review session were available to join
About Slave Zero X
“There blows the neighborhood: Slave Zero puts you in command of a hijacked 60-foot biomechanical war machine geared to overthrowing SovKahn, an evil dictator who policies futuristic town S1-nine with an iron fist as well as a buttload of robots. Outfitted with rocket launchers and equipment guns, you must ruin electricity crops, hovercraft, skys