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.
Pick up twelve toasted sandwiches.
Complete every level without using the time slider.
The gnome must be cast back into the fiery chasm from whence it came.
Collect 75 robot heads.
Propel your vehicle 150 meters into the air, using any means possible.
Fall into a pit of lava 3 times
Sound the bell ten times within ten seconds.
Collect 20 robot heads.
Destroy a robot using a robot head.
Perform a 540 degree flip in a vehicle.
Destroy five robots in two seconds.