I was looking at a MOD called Shaft and I saw they added Stuka-bats to on a rail.
I thought it actually made perfect sense alien bats chasing you down the tunnels whilst on a train. As you drive near them they unpin themselves from the ceiling and come after you.
It’s basically a major part of the game play of that chapter which is missing… An enemy that can actually make chase while you are on the train. Shoots at you hangs from the ceiling and hard to shoot possible whilst up there.
I looked over your level and I think what you have done is very good. If I would critique the design there would be 3 things I would change.
I would keep the Rocket at the end of the chapter entirely and Remove the outside train Yard entirely. The Rocky Tunnel was quite nice though and the Puzzle after the massive Yard.
I would Remove the whole Cafeteria Store Room Fight and Replace with A section Similar to how Route Canal Works. Jumping onto a moving train with Carridges to Get to another Area which is otherwise inaccessible. Then have to fight across the Tracks the other side. Distance Fight with enemy in Cover. Like they are now Chasing you down.
I would Remove the whole Lights Off Fight and keep very simple and use this point to join to the Last Default On a rail map with the Rocket. The Bit I like is where you can Shoot the Other cart with soldiers and then Jump off yours and then on to the Other Cart. That is Cool Gameplay… Perhaps a disaster needs to loom at the end of the track the player is on here such as a deadly drop where the track is broken meaning you have to pull off the Jump to the other Cart as a means to progress and avoid death.
The Parts Where you are on the train Are Good you did and the Lift Sections and so on what I am saying is keep the rocket at the end but extend the Journey add Stukabats as perfect enemy for on a rail. Use of more Barnacles also. rather than having to keep stop start stop start.
More Tunnels you Have to Smash Through i.e. Boarded up. Shooting the Odd Switch to change the Tracks.
A Hecu operated Tram following Behind you also would be beneficial to adding to the Chase.
I defo mean Stukabats and not the Flocking Floaters… Flocking Floaters look bad.
Perhaps a 180 degree turn Crouch Button is needed for the Train Vehicle to make game play swift when in control of speed… At a single push of a button you can crouch and look behind you say shift. would work for that.
I would go with HECU Sentry Drones over Flocking Floaters… I see somone added Flying Turrets to a MOD and this would also serve a similar Purpose. Drone Turret basically. Manhack sort of thing. They just Float and shoot but can pivot the Gun they activate on the Red Laser Triggers.