Copy machine, Tumbleweed Terror, Experiment 78
Is it a coincidence that these 3 items, all of which contribute to Gravity Falls weirdness, are hidden in plain sight in the Mystery Shack? Of course not!
Naw, that's the normal amount of green lightning.
I know every inch of this machine.
The only real explanation for this is that Soos has played the game before, got the high score, was zapped into the game, and turned the power off, thereby eliminating his high score and prompting him to try for it again.