When you land on the floor, move to the right until you see a vertical elevator moving downward. Jump to the top and continue to the right.
When you see the firs TV in the corridor, you can destroy it to turn into a drill. Use it go go downward.
In the following room, ride the elevator to the top and head to the right. Destroy the TV to become a bomb and open the nearby wall. Go through to the boss section.
At the end of the level is a large enemy. It is large and will normally advance slowly. As it approaches or as you near the edge of the arena, it will charge forward. Leap over it using the double jump.
This enemy is vulnerable to attacks on its head, either from the double jump or by shots. When it, it will retaliate with a volley of close-range attacks, dodged by running away.
When destroyed, the day is complete.