well i can tell you something that might help you, i have the same issue and i explored.
there is a area where there is a big platform going across the room and one enemy is on it. there is a hole in the ceiling you can throw yourself into, and also get a gun to use as a object to throw yourself with.
then you walk across a huge area, just keep walking. then you get to a wall with lights, use the gun to throw yourself over it.
there is a area with some props and you drop down a bit and there is a big ramp, i used some objects to throw myself up that ramp and it leads to a vehicle tutorial area,
there is also a crawlspace going under a door wich leads to a giant ocean area that leads to nowhere i believe. i died or soemthing while trying to explore more so i havent found a enemy but i feel like it might be there. actually i can try all of that again and see if i can find the enemy there.