Life Refillers
1 in second white windowed building
1 in secret room on subway roof
1 on top of last building in the docks
1 in secret passage in the lab
1 in secret passage in the sewers

Items
Super web on top of last building in the docks
Web Shield in secret room in sewers

Defense Raisers
2 in secret room in sewers
1 in farthest point right in city (swing from Connor's Lab)
ATTACK raisers: 1 in lab
2 in secret rooms in sewers

Level
The secret level is only found at night. Go to the daily bugle after you see the docks (DO NOT defeat Venom at the docks) and go to the farthest point on the left. Jump over the white barrier and there will be a pipe. Use the drop down method and have fun !