I beat Tesla when this game first came out, no achievement now though :(. Don't feel like grinding out brick break for the next couple hours to get it now.
I genuinely don't see how this game got a 4.1 rating. This entire series could have been combined into a single game, maybe got more attention, add some interesting mechanics.
the last 10 or so levels feel more like kid's jigsaw puzzles than they do isometric puzzles. ooo, i found the giraffe's yellow spots, and they go right here! now, where are those pesky blue spots?
The most difficult part about this badge/game is that the puzzle gets small, which strains your eyes pretty bad. I have my frame zoomed in about as much as I can and I am still squinting.
By far, the easiest way to get the hard achievement is by just camping in one of the corners once the spawns overwhelm your ability to play. I have tried a few different strategies now, and none compare.
Once you followed the Facebook walkthrough, you have to connect the evidence about Yeow to make deductions that incriminate Yeow. Once you have the 5 deductions in the bottom right about Yeow they will connect to form a theory about Yeow being Pumpkinhead. Once you verify the theory the final cutscene will pop up.
 "Tesla8"){kind=icon}
 "The Journey Home"){kind=icon}
 "Scalak"){kind=icon}
 "Tough Growth"){kind=icon}
 "Holyday City Reloaded"){kind=icon}
 "Where Are My Pets?"){kind=icon}
 "NGU IDLE"){kind=icon}
 "Cubito Mayhem"){kind=icon}
 "Soul Mirror"){kind=icon}
 "Choppy Orc"){kind=icon}
 "Cardinal Chains"){kind=icon}
 "Greedy Mimic"){kind=icon}
 "Temple of the Four Serpents"){kind=icon}
 "Labyrneath II"){kind=icon}
 "ZS Dead Detective - Pumpkin Dead"){kind=icon}