Here is the full list of all 12 Doc Clock: The Toasted Sandwich of Time achievements.
Sit in front of a TV for five minutes.
Complete every level without using the time slider.
Collect 75 robot heads.
Pick up twelve toasted sandwiches.
The gnome must be cast back into the fiery chasm from whence it came.
Propel your vehicle 150 meters into the air, using any means possible.
Perform a 540 degree flip in a vehicle.
Collect 20 robot heads.
Sound the bell ten times within ten seconds.
Fall into a pit of lava 3 times
Destroy a robot using a robot head.
Destroy five robots in two seconds.