Is the word playground?
This is an interesting guess. Lets try to figure out how he deduced this. Then, we can see who doesnt fit in with this guess and possibly have an idea on who final shock is.
People that fit "Play"3.) moehrpi -
game, throne
6.) Linkcat -
Mario, pulchritude
7.) MasterWalks -
Skyrim, fart
People that fir "Ground"2.) CrockettRocket -
rock, me
9.) serprex - heal,
stonesPeople that dont fit in either1.) Coffeeditto - movement, square
4.) ddevans96 - outside, steps5.) Captain Scibra - disc, moo
8.) dawn to dusk - tilt, strong
10.) Submachine - Man, driver
11.) Naii_the_Baf - carry, walk
From what it looks like, dd got to his word by only seeing similarities in the above posts. OR he is trying to hide his shock friend.