This achievement is specific to the PSYCH WARFARE
game mode.* It is cumulative across all gaming sessions.
The enemy grabs the battery and carries it to their brainwashing machine, which is a speaker cluster. Once installed it takes the battery 30 seconds to charge the machine. After that, it begins broadcasting propaganda.
THIS IS THE MOMENT YOU BECOME SLAP-HAPPY, and it lasts for only 25 seconds (or less) per broadcast. All members of the brainwashed team are entranced. Vision is vignetted by a disorienting swirly rainbow, a voice in your head demoralizes you, and your weapons disappear, leaving you only with your own comically flailing arms and legs.
Chase down an enemy (they're all still armed) and pull
to melee attack – do it repeatedly to get those slaps in! If successful, after receiving the normal 100 XP for the kill you'll see an additional SLAP KILL bonus for 250 XP, and in the on-screen running kill tally you'll see the slap symbol:
At the end of the match you can
to see the score breakdown which shows how many slap kills you landed.
To track some
of your progress toward this achievement, choose Track Record > Feats of Prowess > Game Modes > Psych Warfare > Slap Happy. Unfortunately, the Game Modes category of feats (and all corresponding XP bonuses) cannot be accessed until you reach level 35, but the achievement is unlockable from day one.**
As for strategy to maximize successful panic-slap kills, let me say this: It would be really cool
if the brainwashing team would become passive during the broadcast, serving themselves up for easy panic-slap kills (which I've done because I know I'm not the only one who wants this achievement)... but I've found few players who are charitable about this. (Hint, hint, everyone!)
Prepare a DEFENSIVE LOADOUT when entering Psych Warfare, focusing only on what will help you during brainwashing broadcasts. Equip Body Armor as your Support Item. The Fun Facts “Horse Healthy" and “Kinda Bulletproof” increase health and bullet resistance, respectively. Other Fun Facts offer DR to specifc types of weapons. And good alternates are "Fleet-Footed” in slot 1 for extra speed, and "Wooden Legs" in slot 2 to counter a team that's good with traps. Conversely, the following Fun Facts are completely useless during Slap-Happy Time and should be avoided: "Possum Player," "Quick Reflexes," "Mad Bomber," "Marksman," and "Cutthroat."
Perhaps the most important aspect of your loadout is the RAMPAGE, which is earned via death streaks or kill streaks, and activated by using
. The “Angry Hedgehog” (death streak) and “Tough as Nails” (kill streak) rampages award you 75% damage reduction for 15 seconds – invaluable if you time it properly during the trance while near enemies.
Note that when you are killed during the trance there is no
prompt for respawn – you instanly respawn elsewhere, so quickly get back to slappin'!
Because the points system in Psych Warfare rewards the brainwashers, those who are focused intently on the achievement should PLAY TO LOSE. Let
the enemy get the battery and bring it to their machine; do not
interfere with its installation; get yourself killed five times along the way to earn the Angry Hedgehog rampage, then time its use well while entranced.
Keep your eye on the minimap because throughout the broadcast, enemy positions are always revealed as red dots. And for the love of cheevos DO NOT
(as the game suggests) use RT directly on the brainwashing machine to smash it! Shortening the broadcast might be good game strategy, but it's very bad for maximizing Slap-Happy Time!
I was most productive on Crime Alley. Being the most compact map it is amazingly navigable with the Spring Boots. My best single session took place here when I was grossly outnumbered 6 to 1; normally I'd be cursing the poor matchmaking system or imbalance created by bailers, but for the purpose of this achievement I was loving it! I got 8 slaps in, and could've done much better had I not accidentally mistimed a rampage. While they were retrieving the battery and hooking it up I was getting myself killed to earn Angry Hedgehog. Then I'd approach enemies who took defensive positions near the machine – like the roof above (or the hole in the gift shop roof on Amusement Mile). I'd activate rampage, drop down then just go slap-happy crazy! Quite a satisfying achievement.
Sneaky G Wizard has confirmed that accepting the Promotion will erase your progress towards this achievement, so you want to do Slap Happy BEFORE going for
*The brainwashed trance state also occurs in the FUMIGATION game mode, but only at the very end upon defeat, and only for one second. It's such negligible Slap-Happy Time that it shouldn't even be considered when going for this achievement. It is
possible to get one in that second, but when calculating available trance time where 'x' equals the number of broadcasts in Psych Warfare, 25x > 1.
**Thanks to MajorAmok for his initial reporting on tracking the Slap Happy feat. If you reach level 35 prior to unlocking the achievement, the feat's progress will only reflect those panic-slap kills that have been scored since reaching level 35. Unless you scored your very first slap kill after reaching level 35, the count here does not reflect your total progress towards the 50.