Introduction
To achieve the achievement, you must eliminate 50 out of 60 thieves before they reach the presents. On the one hand, it's not necessary to achieve a "Perfect Score" on the stage. On the other hand, killing 50 thieves isn't an easy task and will take some time, even with the tips provided.
Basics
The thieves come in 10 groups, each consisting of a leader and 5 followers. On average, you need to eliminate 5 out of 6 thieves from each group.
The thieves enter Zone 1 (the far-left end of the top row of zones), march right to Zone 5, then turn down to Zone 6 below it, and then march back left to Zone 10, where the Christmas presents are.
When you kill a thief, the rest of the group panics (yellow! above their heads). If you kill another, they become terrified (red! above their heads) and flee.
You must calm the group down after they panic. This is done by sending the alien to a zone.
You CANNOT use traps in the zone where the alien is present.
Important Tips
When entering a zone, the leader moves to a position in the last column (usually in the center row), and the followers spread out randomly. When leaving a zone, the followers funnel into the center row and group together. At this point, timely activation of a trap can kill between 2 and 4 thieves, depending on how spread out they were in the zone. Attempting to use a trap while the thieves are entering the zone or wandering to find spots to wait will kill, at best, 2 thieves (usually just 1).
At the start of the mission, Death tells you that killing the leader of a group slows them down. They will move about 20% slower, advancing through 4 zones compared to 5 zones for a group with its leader. This allows you to group two groups together if desired.
The blue source/pole object in Zone 5 is not decorative. It's a unique trap that summons a UFO, which will transport all the thieves in that zone.
When a group moves from Zone 5 to Zone 6, they are often spread out enough that you can immediately kill the leader in Zone 6 without panicking the last follower of the group.
Strategy
Moving the alien wastes time, so I simply place it in Zone 3 and leave it there.
Groups 1/2 - Tips 2 and 3 are useful together. Kill the leader of Group 1 with the first trap they step on in Zone 1, then completely ignore Group 2. Group 1 will travel a bit slower, so both Group 1 and Group 2 will arrive at Zone 5 at approximately the same time. Activate the UFO trap to kill all 11 thieves. This brings you to 12/12 for the first two groups, so you're already two thieves above the average and can afford to miss a few in the later groups.
Groups 3/4 - Wait until these groups leave Zone 1 or 2, and activate the last trap in the center row as soon as the followers start passing through it. You should kill 3 thieves most of the time. Sometimes you might get an extra one, sometimes you might miss one. But I would say 80% of the time, you'll get 3 thieves. Allow the group to be calmed by the alien in Zone 3, then kill two individual thieves with traps at the top of the lower rows in the future zones. This gives you 5/6 for these two groups.
Note: In my playthroughs, I always used the second trap to kill the leader of the first group, ignored the second group, and killed the leader of the third group with the third trap. By doing this, most of the time I would catch one or two extra thieves with the UFO trap. Try it this way if you can't manage using the above tips.
Groups 5/6 - Do the same as with the last two groups, but use the second-to-last traps in the center row of Zones 1 and 2. You should catch two thieves, sometimes three. Kill a single thief in Zone 4 or 5. This will cause panic among the remaining three thieves. Take advantage of Tip #4 and try to kill the group leaders with the first available traps in Zone 6. If they are spread out enough, only the first of the two remaining followers will flee while the last one will stay just in a panic. Kill them when you want. This gives 5/6 for these two groups.
Groups 7 to 10 - Kill a single thief in Zone 1 or 2. Allow them to calm down in Zone 3. Use the last trap in Zone 4, 5, 6, or 7 to try to kill three thieves as they funnel out of the zone. Then, kill a single thief in one of the later zones.
Conclusion
If everything goes right, you’ll have approximately 50~53/60 kills. Your big advantage will be capturing as many thieves as possible with the UFO. From there, it’s about managing the central zone traps, trying to kill the leaders of the following groups, and with luck, more thieves that follow soon after in the first or second areas. Let them pass through Zone 3 with the alien to calm them down, and from Zone 4 onwards, catch as many thieves as you can when they funnel out of a zone whenever possible. Even if you miss a few thieves, if you managed to catch all 16 from the first two groups, you can afford to miss some and still get the achievement.
Original:
https://steamcommunity.com/sharedfiles/filedetails/?id=32557...