Robots

The robot is a mob in Super Cube Cavern that can be found in both of the current maps, the blue map and the yellow map.

How to defeat
It can only be killed by attacking the robot's back, on the red button. It will not take damage if hit from the front.

You can maneuver to its back by jumping over it or by running around it. Jumping over it may not be easy without boots or a jetpack, but running around it can be easily done effectively, even with the Stone Heart badge.

Note: This may be a nod towards the popular Roblox game The Book Of Monsters, where every monster has a button on its back that you use to deactivate or kill it.