Since I have lost the actual guide and dont feel like routing again, I'll say the basic stuff. (As well as a link to an actual completed run)

In Zone 2, if you go to the entrance to the Residential Area and stand somewhere underneath the window closest to the exit you will get the batter early.

There is an area in Zone 4 where you can click on something to get to level 40. It's in the Military Base, close to the Save Box.

There is a skip in Zone 4 to go straight to the end of the library. At the bottom right corner of the elevator (above the black tile) click and you will get the admin ID card, allowing you to go straight to floor ten.