Junk - Screens 1, 2, and the Elevator

This stage heavily utilizes the Thunder Strike. This is also Junk Man's weakness, so make sure you save enough for the boss. 
 Screen 1 
 Quick Swap to Thunder Strike. Slide, jump, and shoot/zap the first flying enemy. 
 Jump the pit and slide off the ledge, then shoot-slide. The bug should get zapped where a lemon would fly over its head. 
 Continue sliding to the end of the low floor, then full jump on top of the bug-junk-house. You don't need to destroy it and you can walk (and slide) on it. 
 Climb and fall down the ladder. 
 Screen 2 
 Slide through to the elevator door 
 The Elevator 
 Just hang out in the right corner and dodge things. Get through the door on the right as soon as you can.