Just Open all the locked Doors specially the one under the first manhole you find in the same room where you find the coat, You Will get a new battery pack super important for future progress
Also there is a health pack b on a platform at the water plant, u get there by the ladder u climb before the ladder that takes You to building b stairway
Check the ventilation ducts at research lab entrance and detonator room, there is some usefull stuff in the ducts and the excavation place thing
before you continue theres some items that r a bit hidden
Just Open all the locked Doors specially the one under the first manhole you find in the same room where you find the coat, You Will get a new battery pack super important for future progress
Also there is a health pack b on a platform at the water plant, u get there by the ladder u climb before the ladder that takes You to building b stairway
There r other ítems a bit hidden if you wanna know