Just play through the tutorial normally. You'll get the loafers from Mike. You can now slide and walljump on walls (Obviously)

At the end of Board James Stage 1 in the helicopter part, you have to climb to the very top of the ladder to get the Power Glove. You can now press B to punch. It can be used to break blocks and it is required to get the rest of the gear.

Right at the beginning of Browntown 1, there are some breakable blocks on the left wall. Break them with the Power Glove and go into the room. Watch out for the Cacodemon and Death Blocks.
You can now charge up your weapon to deal more damage by holding the X Button.

In Monster Madness 1 after the underwater section. You have to walljump up the wall to the left and break the blocks to get the Cape. You can now glide by holding the jump button while you're in the air...

The Helmet is located in Nerd Gaiden 1. Walljump up the wall to the left at the 3rd checkpoint to walk over the level out of sight. At the other side you have to dodge some Death Blocks and Ninjastars to get the Helmet. With the Helmet, invisible platforms and items will now show up.

The Uber Scope is located at Area 52 Stage 3. You need the helmet and the Power Glove in order to get the Uber Scope. Troughout the level, there is an tunnel with Death Blocks. Invisible platforms will appear over the Death Blocks if you have the helmet. Once you enter the room you have to dogde all the Death Blocks and break the blocks. Now you got the Uber Scope. It does more damage than the Zapper and the projectiles are slightly bigger.

You read this grate guide.
And prooved that you like wasting time f*cking reading sh*t.
Now go f*ck yourself !

Special thanks to WorKSimi helping me out finding all the stuff. Thanks man!