This is the first level in world 1.
This level introduces the mechanic of time flowing backwards for everything except Tim. There is a cannon up at the top of the level which normally would shoot monstars that would walk into a pit full of spikes. However, since time is flowing backwards, the monstars are falling from the bottom of the screen into the spikes, jumping out of the pit, and leap back into the cannon. The cannon and spike pit have a ladder you can climb up to them with.